Wikipedia:Reference desk/Archives/Science/2006 September 10

=September 10=

Insect Costa Rica
These photos were taken at Costa Rica in march. It seems, one is male, the other female. On my mind, it's not a Parascopioricus. Does anyone know the name? --Ruestz 00:33, 10 September 2006 (UTC)


 * Phasmatodea? Great pictures by the way, we'll have to add them when we know for sure. — [ Mac Davis ] (talk) ( Desk | Help me improve )


 * The LucidCentral Guide to Insect Orders is a useful tool for identifying insects to the order level. Unfortunately it doesn't go more specific than that. BenC7 01:32, 10 September 2006 (UTC)

What do snake eggs look like?
I found a partially burried pile of soft, white, oval shaped things on the ground in my yard a few days ago. The "shell" came off easily revealing a dry, yellow, oval shaped thing. Someone told me they were mushrooms but I doubted that. If they are snake eggs, is there any way to find out what kind? I live in North Carolina(eastern US) if it helps. --Isamil 00:47, 10 September 2006 (UTC)


 * Not a very specific answer I know, but: Some animals, including some snakes, have eggs with leathery or other not-so-hard materials for the shell, so snake eggs is a reasonable first guess. Peter Grey 01:11, 10 September 2006 (UTC)


 * More generally, reptile eggs are soft, so they could be turtle eggs or from some other reptile. StuRat 03:08, 10 September 2006 (UTC)


 * A Button mushroom could be mistaken for an egg. 1001001 04:01, 10 September 2006 (UTC)


 * Wouldn't a mushroom have a 'stem' and an egg not? Also, opening it should make it very clear, or don't you want to do that (or even pick it up)? DirkvdM 09:27, 10 September 2006 (UTC)
 * Don't open them, they could be endangered. If you really want to know, you could wait 'till it hatches (that would take a lot of waiting around though). I agree with people here though, it is probably a reptile of some sort. Were they in a hole or resting on the ground? Turtles and lizards generally create a hole or burrow for their eggs. --liquidGhoul 11:49, 10 September 2006 (UTC)

I can't remember ever seeing a turtle in this area. They were partially buried in mulch and were not in a hole. Tomarrow, I'l see if I can take a picture of them. --Isamil 23:25, 10 September 2006 (UTC) North Carolina has venomous snakes as well as harmless ones, so be sure not to stick them in a box under your bed and forget them. Edison 04:48, 11 September 2006 (UTC)

See http://wildwnc.org/natnotes/unearthly.html for info about snake egg clusters yu might find in North Carolina. This nature center in Buncombe County might be better able to advise you. Edison 05:02, 11 September 2006 (UTC) That helped, thanks. The article says no venomous sankes in this area lay eggs, so I suppose I'l just leave them there. Isamil 19:03, 11 September 2006 (UTC)

Salty Fish
Since lots of edible fish live in saltwater, why do the fish themselves not taste salty?--Light current 00:57, 10 September 2006 (UTC)
 * They don't? I think most of them taste salty to me. Anyway, the fish has a constantly active salt-getting-out system, because it would die if it had too much salt. — [ Mac Davis ] (talk) ( Desk | Help me improve )
 * Though at the same time, the salt levels in their body are much higher than freshwater fish, which is why they die if put directly into freshwater. freshofftheufo  ΓΛĿЌ  07:58, 10 September 2006 (UTC)


 * ... because the inside and outside wouldn't be isotonic. The salty fish would absorb too much water and 'blow up'. Conversely, a sweet water fish in fresh water would shrivel. Few fish manage to migrate from one environment to the other, like salmon. I don't know how they do that, though, and the artiocle doesn't seem to say either (just skimmed through it). DirkvdM 09:31, 10 September 2006 (UTC)
 * The term is anadromous but clicking on that gets a bad article on fish migration, not any physical details. Rmhermen 02:58, 11 September 2006 (UTC)

So when these fish blow up, do we then call them bloaters?--Light current 10:25, 10 September 2006 (UTC)

How do I tell the difference between male and female gulls?
Anyone know? They all look the same to me. --84.65.209.240 01:11, 10 September 2006 (UTC)


 * Which particular sort of gull did you have in mind?--Light current 03:26, 10 September 2006 (UTC)

Bouys versus gulls?Edison 04:55, 10 September 2006 (UTC)
 * Some birds are very difficult to tell apart externally, though I'd bet in gulls there's some very specific (though relatively small) difference, e.g. beak color, color pattern, body frame. In order to tell the difference in cases where external inspection isn't reliable, blood or tissue samples may be required. freshofftheufo  ΓΛĿЌ  07:56, 10 September 2006 (UTC)


 * More to the point, how do gulls themselves tell the difference?--Shantavira 08:30, 10 September 2006 (UTC)


 * Maybe they don't and just give it a try. Getting it right half the time should be sufficient to keep the species alive. Of course this would also mean that male gulls get butfucked a lot, but hey, if that's their thing. Some humans even like it. (Sorry about being such an open minded Dutchman again. :) ) DirkvdM 09:37, 10 September 2006 (UTC)


 * I'm no scientist but I'm guessing that the gulls themselves know their own sex... :) --Kurt Shaped Box 11:21, 10 September 2006 (UTC)



thumb|100px|left|Male Gul

They look rather distinct to me. :-) StuRat 09:33, 10 September 2006 (UTC)


 * So they're distinguishable by the number of l's in their names? DirkvdM 09:41, 10 September 2006 (UTC)
 * What if they can't spel? DirkvdM 13:37, 10 September 2006 (UTC)




 * User:Freshgavin is correct - if you watch a breeding pair of gulls (herring gulls and GBB gulls at least) stood next to each other, 9 times out of 10, the male will be longer, wider and with a slightly bigger beak. It is very hard to tell sometimes though, unless you spend a lot of time watching them - and completely impossible when there's a big flock milling around. --Kurt Shaped Box 11:21, 10 September 2006 (UTC)

SPSS graph
Is it possible to do a histogram or bar chart with SPSS for a grouped frequency distribution table? -- Hersheysextra 01:35, 10 September 2006 (UTC)

Songs that break music theory rules
I was having a debate with my friend. He claims that music is a science, and that every song that sounds good in the world, follows the rules of musical theory. ie, every note is in the right key. Evry note is in perfect pitch. Now, I can't imagine that out of all the millions of songs in the world, there isn't at least one, that breaks at least one of these rules, while still being considered by at least some people, to be a good song. So, my request is, does anyone know any song like this? Personally, I have no knowledge of musical theory, but I do listen to a lot of music, and I think, music, like any art form, is subjective.--Richy 02:20, 10 September 2006 (UTC)
 * Depending on what era of music you live in, there are different rules. Depending on the culture you have different tastes. In the Far East, they like pentatonal systems, in the Middle Ages, Western harmony featured the perfect intervals of a fourth, a fifth, and an octave, and the rest were called "imperfect." Western tradition focuses on harmony and counterpointing, and in recent years we have grown to place attention on the melody of the song over whatever beat or chords might be playing in the "background." Think of a favorite rock song—you can probably remember the tune, but not necessarily followed the drummer's skills the whole song. — [ Mac Davis ] (talk) ( Desk | Help me improve )


 * There are not very many music theory rules, and in fact the best music is often that which artfully bends the rules. Music that follows the 'rules' can be good, for instance some of the best rock and roll is perfect 4/4 time and uses only two or three chords. But some of the best pop songs go 'out of key' and time; Peter Gabriel's Solsbury Hill and Pink Floyd's Money (song) are both in 7/8 time; Michelle (song) by the Beatles, My Little Town by Paul Simon, and lots of other famous pop songs go 'out of key' (other than modulation, going up by a half-step for dramatic tension). He's not so well-known now, but perhaps the greatest songwriter of all time, Cole Porter, was very musically complex, going out of time and key all the time. And of course classical composers did it, Beethoven in the Presto movement of his Ninth Symphony, and all our favourite modern movie composers (the Imperial March, otherwise known as Darth Vader's theme, is a great example, as is a lot of Danny Elfman's stuff). Hope that helps. Also, another John Williams example is the Across the Stars love theme, which artfully changes key about 4 times. Anchoress 02:40, 10 September 2006 (UTC)


 * Who said 4/4 is better than, say, 6/8 (favorite of Elfman if I remember correctly), which is also "standard?" — [ Mac Davis ] (talk) ( Desk | Help me improve )
 * I certainly didn't say that. But 5, 7, 11, etc are considered 'odd' times, unlike 2, 3, 4, 6, 8, etc. Anchoress 02:56, 10 September 2006 (UTC)


 * There are certainly conventions to music composition. They can and often are broken. Even the notes we define as notes (ie., what frequency we define a C to be, and so on) are not always followed, and not even in the Western oeuvre of music either. Dysprosia 07:54, 10 September 2006 (UTC)


 * About a century ago, some classical musicians decided that it was tome for 'out with the old an in with the new' because the rules were too strict (and indeed tehy were). But it was difficult to persuade composers to break with tradition, so they made new rules to replace the old ones. And some pretty stupid ones, leading to stuff like atonal music. I've heard some of it and it sounds like a pile of shite to me. DirkvdM 09:48, 10 September 2006 (UTC)


 * And those too were broken. Serial music has fallen somewhat out of fashion; focus these days seems to be on neotonality. Dysprosia 11:33, 10 September 2006 (UTC)


 * Not enough for there to be an article on it, though, it seems. DirkvdM 13:39, 10 September 2006 (UTC)


 * Of course, the absence of a Wikipedia article doesn't imply a lack of popularity in the real world; this is a whole other topic entirely. Dysprosia 02:36, 11 September 2006 (UTC)


 * If it were popular, wouldn't there have been at least a stub on it by now? Or are musicians underrepresented on Wikipedia? DirkvdM 08:21, 11 September 2006 (UTC)


 * To be brief on this (here is not the place to be discussing this point), it's probably for the same reason that Pokemon and other television shows are well documented while information on the arts is severely lacking. Dysprosia 03:55, 12 September 2006 (UTC)


 * As Anchoress already said, good art bends the rules. More precisely, it finds the right balance between following and breaking them. What the right balance is depends on the audience (or the artist, really). Some people prefer simple easy listening music. An extreme example is muzak, which is more a utility than art. At the other exteme you find exprimental jazz or atonal music, which I already mentioned. (btw, in pop music there is a differnce across the Atlantic, with US music being 'easier' and European music more experimental.) But there must be some rules. Take rhythm. It's usually 4 or 3 based (or multiples thereof) and occasionally you get 5 (or, rather, take 5 :) ). 7/8 is already weird, so making that work in an easy sounding pop song (as in Pink Floyd's 'Money') is a sign of sheer class. Flamenco uses some unusual rhythms too, eg 12 beat, but not quite - 3-3-2-2-2 (one, two, three - one, two, three - one, two - one, two - one, two). Indian (improvised) music seems to have very relaxed rules. I once heard a player say that if during a concert two players end up playing the same rhythm, that is a happy coincidence. I have spent about a year composing music and I like to bend the rules. One little peice I called 'blues without a rhythm', which is exactly what it is. Then agian, there is a constant hint of a rhythm, but it keeps on losing it and then finding it again, or another rhythm. If there were no hint of a rhythm at all, it would be cacaphony. But following the rhythm too precisely kills the music, a crime committed by most classical performers.
 * MacDavis already mentioned that almost all intervals were considered bad in the middle ages. Such as the third. Hell, you can't even make a major chord without that. Let alone a minor chord. And Mozart did something revolutionary when he used a seventh in a peice. Nowadays music that doesn't use that all the time would be considered dull. i once heard that the worst interval is the diminished fifth. So I decided to base a piece of music on it. But prettty soon I discovered that it was really based on the fifth, with the diminished fifth being a variaton of that, one that created tension that had to be resolved. And that last bit is very important. The rules are something you fall back upon, but it's the temporary deviation that makes the music interresting.
 * I could go on about this for a very long time. Music is the best combination of science (math) and feeling there is. It makes the basic human thought paterns (intelligence) explicit more than anything I can think of. DirkvdM 11:29, 10 September 2006 (UTC)


 * Listen to 'The Black Angel's Death Song' by The Velvet Underground. :) --Kurt Shaped Box 16:58, 10 September 2006 (UTC)

A few months ago, on NPR, they talked about music theorist Dmitri Tymoczko, who recently wrote a paper describing a new type of geometry he had created to represent music. There have been all kinds of music geometries to represent music, but none of them got it "all" right, but his apparently does. His paper was accepted to Science magazine, the first music theory paper they had ever published in 120+ years. In that paper, he says that Chopin's piano prelude in E-minor (Opus 28, No. 4) is the make-or-break song. Apparently most predictors indicate that song should sound like crap, but it sounds fairly good. Raul654 17:06, 10 September 2006 (UTC)

The wiki page on Time signatures talks about lots of the non-"standard" ones. DMacks 21:35, 11 September 2006 (UTC)
 * In fact, we have a whole separate article on them: List of works in unusual time signatures. JackofOz 20:53, 13 September 2006 (UTC)

Interior Plains of the United States
My 4th grader need to research information regarding interior plains in the United States. We were able to obtain information on the wiki under great plains. We are lookin for answers on specific questions such as:

1. What forces of nature cause the interior plains of the United States to be formed or in other words, how did it develop> 2. What is unique about the interior plains? 3. What efforts are being made to preserve the inerior plains?

My 4ht grader went to the library and they do not have any materials in plains under landforms. Please help her.

Thank you very much.
 * This is an encylopedia, and you can just type in "Interior Plains" in the Find box in the left. Push go, and you're there. :) — [ Mac Davis ] (talk) ( Desk | Help me improve )


 * The Geologic Story of The Great Plains will help with 1 and 2. On 3, there are U.S. Grants available for Conservation of the Great Plains 1001001 04:12, 10 September 2006 (UTC)

irrigation engineering
what are the types of irrigation systems?

See our page on irrigation--Light current 05:04, 10 September 2006 (UTC)

dynamic hermaphroditism
Okay, there are sequential hermaphrodites that change sex as part of their life cycle, and simultaneous hermaphrodites that have both sex organs; but is there such an organism that dynamically changes its own sex based on current population sex ratio, environment, available resources, etc. ? Phoenix-forgotten 05:37, 10 September 2006 (UTC)
 * There are cases of evolutionarily 'unintended' hermaphroditism caused by environmental stress such as polybromated diphenylsin polar bears. But I doubt this is what you were looking for.---Sluzzelin 11:23, 10 September 2006 (UTC)

Sure. alteripse 11:29, 10 September 2006 (UTC)

Cell phone batteries
Is it true that if your current cell phone you use breaks and it is not repairible that the battery can be placed in another phone and all your data remains or is saved on the new phone.--Biggie 05:49, 10 September 2006 (UTC)
 * No, batteries have no capability of storing information in such a way. Even if there was a battery that was for some reason attatched to a memory chip, it would probably only work in the exact model of phone that it was constructed for. freshofftheufo  ΓΛĿЌ  07:49, 10 September 2006 (UTC)


 * Battery, no. SIM card, yes, to some extent. Phones permit you to save data on the SIM card, which can easily be transferred. Dysprosia 07:54, 10 September 2006 (UTC)

Thanks for the info--Biggie 08:49, 10 September 2006 (UTC)


 * Battiers just provide power to the phone. --Proficient 06:15, 11 September 2006 (UTC)

An amp's power consumption
Suppose I have a 100W amp. Does it draw 100W all the time? Or does that depend on how far I turn the volume up? Or even how loud the music is (the dynamics of the music)? I suppose the former but not the latter. If I set it at half the maximum volume, measured by subjective perception (it sounds half as loud). Is the power consumption then half of what it would be at maximum volume (so 50W). I'm pretty sure not (much less), but what is it then? DirkvdM 09:08, 10 September 2006 (UTC)


 * Yea, that's the maximum. Whether you reach the max would depend on both the volume of the recording and the volume setting on the amp. StuRat 09:13, 10 September 2006 (UTC)


 * If its class A, yes it will draw constant power wasting whatever doesnt go into the speaker. But if class AB (which has a max efficiency of 78.5%), then the power consumption is almost proportional to the power in the speakers (and hence the volume). In a class AB amp, there will be some constant power dissipation not related to the output power, but this will only be a few watts at most. See electronic amplifier--Light current 09:23, 10 September 2006 (UTC)


 * THe question of efficiency vs output power, Im not certain of.--Light current 09:43, 10 September 2006 (UTC)

In general electronic equipment may draw far more electricity than its rated output. High fidelity is a bigger goal with audio than efficiency. Any heat given off is the result of that inefficiency.Edison 19:29, 10 September 2006 (UTC)

gravitational waves and propulsion
Im aware that none of the machines that claim to produce these waves have been varified, but they exist right? What is the mainstream physics communities views on gravitational waves being used for propulsion or moving objects in the future? and are these the waves produced by gravitoelectromagnetism?

Robin


 * Well, gravitational radiation is produced whenever a mass accelerates, but for everyday masses and accelerations the waves are unobservably small. To produce enough gravitational radiation to detect, you need huge masses accelerating very fast, like binary neutron stars spiraling towards each other. (The reason they spiral towards each other instead of staying in a stable orbit is exactly because they emit gravitational radiation.) I did find a paper with the exciting title Gravitational radiation and its application to space travel, but it's all theoretical so far. —Keenan Pepper 16:18, 10 September 2006 (UTC)


 * Keenan Pepper is absolutely right about the mechanisms behind gravitational radiation although it's probably worth pointing out that motion in a circle is acceleration (lay-people, particularly argumentative ones, sometimes disagree with this). I haven't read the paper, but I can't imagine gravitational radiation being terrible useful for space travel as it is really rather weak.  If it were to be harnessed then the first step would be to use it to transmit information.  Its real worth will be (at least initially) for observation as it will allow us to see back into the radiation dominated period of the Universe.


 * Keenan, do you have an arXiv citation? This sounds like some presumably unpublishable (since terribly wrong) eprints I have seen there.


 * Robin, the mainstream view is that gravitational waves interact very, very, very weakly with matter and cannot be used in any practical way to manipulate matter or for spacecraft propulsion. There are some papers out there by physicists (and even non physicists) who are too inexperienced in the ways of curved spacetimes to avoid confusing "coordinate effects" (artifacts of a mathematical representation, which have no physical reality) with genuine physical effects.  The very fact that LIGO requires such extraordinary efforts to detect even the strongest gravitational waves ought to tell you something!  See for example this readable expository paper by Kip Thorne. ---CH 03:47, 18 September 2006 (UTC)


 * I have a rock that creates a gravitational field around it. HighInBC 00:02, 21 September 2006 (UTC)

We're out of transcluded pages
So, what happens now? Do we just delete old posts?--205.188.116.74 13:56, 10 September 2006 (UTC)


 * Erm, I'm not sure I get what you mean. If you mean you can't transclude more templates than we have right now, we just archive the oldest day (it may even be done automatically), but I don't think we're out of transcluded pages. The max. limit was raised, and I doubt we hit it. - 87.209.70.231 14:05, 10 September 2006 (UTC)


 * I believe he means that none of the Ref Desk pages currently include any transcluded pages pointing to archive pages. In this case, instead of just removing the transclusion, we need to first create the archive page, then remove the day from here.  I believe this will need to be done manually, as the bot that did this is no longer running. StuRat 00:10, 11 September 2006 (UTC)

Sexual Advice
Que: Can a curved penis be made straight with the help of surgery? —Preceding unsigned comment added by 59.144.180.72 (talk • contribs)


 * Probably, but we can't do that here on the desk. Take it to see a doctor.--Shantavira 16:43, 10 September 2006 (UTC)


 * I think so. Is it really worth the pain, hassle and expense though? Supposedly most men's cocks bend either to the right or left when erect. How 'curved' are we talking about? --Kurt Shaped Box 16:55, 10 September 2006 (UTC)


 * Apparently bent ones offer a better experience for the woman... obviously not to bent... but yeh, anyway, you may just be being to self conscious. Philc  TECI 17:26, 10 September 2006 (UTC)


 * Penises are rarely straight; they don't need to be for good sex. I wouldn't worry about it. If you do, bring it up with your doctor. He's the only one who can decide if surgery can be done and if it is needed. - Mgm|(talk) 19:46, 10 September 2006 (UTC)
 * if it's needed!? are you kidding me I'll get surgery if I damn well want it and can pay the money for it. Jasbutal 21:10, 10 September 2006 (UTC)
 * Youd be surprised, doctors do have the right to refuse to perform surgery you know, their not legally bound to straighten your penis on demand you know. Ususally you wont even know if they have refused, because they would have just had a few sessions with you, and chatted about what you want done, and by the end of it convinced you that you dont want surgery, because usually they're right. Philc  TECI 21:44, 10 September 2006 (UTC)
 * let's just get something straight. The guild-like AMA and all member doctors chose their profession for the respect and the money. Trust me, you offer the money and you'll be able to find an AMA doc to do it for you. Jasbutal 04:44, 11 September 2006 (UTC)

Guys, we tell our ref desk clients to seek appropriate professional advice about medical, dental, or legal matters. That means that we shouldn't be entering into debates about the merits or otherwise of such surgical procedures. Shantavira's reply was the perfect one. IMO, everything since then has been inappropriate. JackofOz 01:35, 11 September 2006 (UTC)


 * Wow. I didn't know that. --Proficient 06:16, 11 September 2006 (UTC)


 * Anyone with half a brain should understand that this is not a medical ref desk. If you get an expert reply you're lucky. Most answers will be educated guesses that might point you in the right direction. By your reasoning we shouldn't have any medical articles either, unless it has been established beyond doubt that the autors are true experts on the subject at hand. DirkvdM 08:32, 11 September 2006 (UTC)


 * I agree. You don't have to be a man interested in straightening his curved penis to be curious about whether curved penises can be straightened.  It's an encyclopedic question, so it's within our domain.  We should always be careful to remind people that we're no substitute for doctors, but as long as we do that, I think we should feel free to try to figure out answers.  --Allen 08:54, 11 September 2006 (UTC)

What I'm talking about is practising what we preach. People often get abused around here when they ask a question without first doing a search. I don't agree with the abuse part of it, but the central issue is that there are guidelines that questioners are asked to read and abide by. Fair enough. Well, guidelines work both ways. The other side of the coin is that we can hardly ask them not to expect medical, legal or dental advice here, if we in fact tender such advice in response to a question. Every time we break our own rules, we undermine our credibility. That's my main concern here. JackofOz 07:28, 12 September 2006 (UTC)


 * Check out Peyronie's disease. Also do a web search. 68.183.136.15 01:44, 13 September 2006 (UTC)

Curvature of space and time
What is the simplest way to understand the concept of space-time and its curvature?

the ? varible is part of the experiment that is affected by the independent varible. if you could help please. thank tou


 * Think of it in terms of a man's penis - supposedly most men's cocks bend either to the right or left when erect. I think space-time curves in the same manner. (sorry, that was a silly answer - but I couldn't resist) --Kurt Shaped Box 17:02, 10 September 2006 (UTC)


 * Well the ubiqutius explanation of general relativity is probably found at the article. It concerns a latex sheet representing the spacetime continum, and masses bend the sheet, curving it, and that is a gravitational field. — [ Mac Davis ] (talk) ( Desk | Help me improve )


 * The rubber sheet is an reasonable simplification - as with most concepts of curvature in three (spatial) dimensions removing a dimension helps people to visualise it. As an undergraduate, one of my professors told me that to visualise the curvature in three dimensions is impossible.  However, I find visualising a gravitating body as stretching spacetime by pulling it towards it (pulling more strongly nearer the body and less further away - inverse square law) makes for an acceptable visualisation.  I justify this by imagining a triangle being stretched in just such a manner - the internal angles will equal less than 180˚ - demonstrating just such an hyperbolic geometry as is associated with a gravitating body.
 * For most people it is not possible to visualize the three dimensional negative curvature, but it is better to do that if you can. I *think* the easiest two ways (I have made them myself and never told anybody before) are to imagine the flat sheet, and one that is perpendicular, along the z axis. Stick Earth right inside that corner, and see the dip. Or you could imagine something like the Earth as a spikey ball, and the (hollow) spikes being like a tangible gravitational field. Kind of like sticking your finger into the Earth and the paper turning into the shape of your finger, flairing at the edges. — [ Mac Davis ] (talk) ( Desk | Help me improve )


 * I'm not sure what the advantage of having two sheets is over the single sheet - having two sheets is still a two dimensional representation just with a fold. A complication which, to me, doesn't have any advantages.  As for the 'spiky ball' explanation, I have never heard of anything like that for explaining curvature and I'm not really sure what you're getting at with it (this is not a criticism).  In my experience, the problem most lay-people have with visualising curvature in three dimensions is that they don't try to think of it in terms of the geometrical properties of the curvature.

Direct gene transfer using PEG and Calcium chloride
Sir/ Madam, I will be benefitted if I get more information regarding and related to this subeject.


 * We don't seem to have an article on your meaning of PEG, and Calcium chloride has just a couple of sentences: "Aqueous Calcium Chloride is used in genetic transformation of cells by increasing the cell membrane permeability. This allows DNA fragments to enter the cell more readily." The reference isn't given. Melchoir 21:30, 10 September 2006 (UTC)


 * The PEG in this case is polyethylene glycol, linked from the dab page at PEG. What the original poster really needs here is either a good laboratory manual that describes the process in detail, or (ideally) a local colleague who has experience with transfections and can provide a protocol. TenOfAllTrades(talk) 21:45, 10 September 2006 (UTC)


 * Ah, I was thinking PEG would be a three-word name of a technique. Melchoir 21:47, 10 September 2006 (UTC)

Helium Balloon questions
1. What would a helium balloon do in gravity-less outer space?

2. What ratio of regular air to helium should go in a balloon so that it floats in the air stationary? Thanks! Reywas92 17:45, 10 September 2006 (UTC)


 * 1. Unless it was quite strong, it would burst (without a bang).
 * 2. It doesn't matter. Assuming it gets off the ground it will eventually reach an altitude at which its weight is balanced by its reduced lift in the rarefied air.--Shantavira 18:19, 10 September 2006 (UTC)

A helium balloon in space would inflate to the same size as on earth if the pressure differential were the same between the inside and outside. So if atmospheric pressure is 14.7 pounds per square inch or 101.325 kPa, and the balloon inflates to 1 foot diameter on earth, in space for it to inflate to 1 foot the internal pressure would have to be reduced by 14.7 PSI. Now consider temperature: if the balloon is in the shade, it will radiate off heat, become cool, and shrink. The pressure would decrease in proportion to the drop in absolute temperature, PV=nRT per the Gas laws. If the balloon is in the sun, it would heat up and expand. If it were in the International Space Station or the Space Shuttle, it would drift with air currents, with no particular tendency to rise to the ceiling or sink to the floor, since these surfaces would be interchangeable. If you untied the stem and let the helium spurt out, it would take off like a rocket, since Newton's Third Law says To every action (force applied) there is an equal but opposite reaction. The lack of a surrounding atmosphere for the balloon exhaust to "push against" would not invalidate this law. If you stuck a pin in it, it would burst, but silently,since there is no air to transmit sound. Echo 1 (seeEcho satellite) was a plastic mylar balloon put in space as a passive communication satellite in 1960 which lasted until 1968. 100 feet across, it was easily seen with the naked eye when in the right portion of the night sky to reflect sunlight. It can be seen at http://www.scienceandsociety.co.uk/results.asp?image=10300344&wwwflag=2&imagepos=1 No info on whether it was inflated with hydrogen or another gas, but a gas with larger molecules might not have diffused out through the skin as fast.Edison 19:53, 10 September 2006 (UTC)


 * It all depends on how big the ballon is, as its area (i.e. the weight of the skin of the balloon) goes up in squares, while the capacity cubes. So there is no one answer, though a formula could probably be concucted. Philc  TECI 21:52, 10 September 2006 (UTC)

Question about Sinusitis
I've had sinusitis before (eleven times in one year, at one point) and I'm fairly sure that it's not contagious, but I'd just like some verification, because this could be old information. Is sinusitis contagious, and if so, how contagious is it? Thanks in advance!!  Srose  (talk)  19:01, 10 September 2006 (UTC)


 * Contagiousness relates to spread of a disease from one person to another. Sinisitis can be infectious, but results mostly from bacteria already resident in the sinuses rather than "caught" from other people. You need to ask your physician what is causing you to have chronic sinusitis and what can be done about it. - Nunh-huh 19:16, 10 September 2006 (UTC)

Get your medical advice from a physician. 11 time in a year is way too much. See an Eye Ear Nose and Throat specialist. But from personal experience, there may be things he can do to alleviate the condition. Sinusitis can lead to some very bad things, such as meningitis.Edison 19:56, 10 September 2006 (UTC)


 * Thank you both very much! I've replied on your respective talk pages.  I do get most of my advice from my physician and the specialists that I see, but of course they're unable to answer questions on a Sunday! :) Anyway, I'll repeat myself and say: thank you very much!  Srose   (talk)  22:20, 10 September 2006 (UTC)

If you have an allergic or autoimmune form of sinusitis, then it's not contagious, but it may be if you have a fungal, viral, or bacterial form. StuRat 23:28, 10 September 2006 (UTC)

See a pulmonary or ear/nose/throat doctor. If we start giving advice it will include some unpleasant possibilities. alteripse 00:36, 11 September 2006 (UTC)

What is insect hair largely composed of?
I know mammals have hair composed mostly of keratin. Many insects, like this moth, also have hair. Is it made of chitin, or some other substance? Gary 19:10, 10 September 2006 (UTC)


 * It's chitin. - Nunh-huh 19:12, 10 September 2006 (UTC)


 * Thanks! Do you have a source, by any chance? Gary 02:53, 11 September 2006 (UTC)
 * Here is one — [  Mac Davis ] (talk) ( Desk | Help me improve )

How to tell if watermelons are ready to harvest?
I have this year learnt how to grow plants from seed. For fun I bought a packet of melon seeds and planted them in pots - I do not remember how long ago. I have three green melons about four or five inches in diameter.

How can I tell when I should harvest them please? As I am in the UK they may not grow as large as the watermelons for sale in supermarkets, as the latitude (or maybe I mean longitude?) here is about the same as Newfoundland and hence the sun is not as powerful.

As I noticed that something had eaten into the rind of one of them, I did cut that off the stalk and sliced it open and ate it. I realised it was a watermelon. It was pink inside with seeds, and was moderately sweet. So now I've got two left. Will they grow any more or should I harvest them now?


 * If the first watermelon seemed ripe, I'd harvest the other two right now, especially since it seems they may be eaten by something, if you wait. StuRat 23:22, 10 September 2006 (UTC)

If you don't harvest them in time, they reportedly become vampire watermelons. Be careful. alteripse 02:28, 11 September 2006 (UTC)

The ones we grew were way bigger than what you described, so may be a different type. You can tell when a melon is ripe by thumping it with your knuckle. An unripe watermelon, not yet red or sweet will have a relatively high pitched clear sounding thump. A ripe watermelon will have a dull and lower-pitched thump, probably due to the appearance of cracks in the interior or to the higher sugar content. If there are smaller and greener melons, these will grow and ripen unless the temperatures have dropped. Melons ripen best on hot days with full sun. If the vines and leaves look brown and dead I would not expect any more ripening. They will eventually rot if not picked when ripe. I do not believe they continue to ripen after picking. They can be stored for days in a refrigrator. Enjoy!Edison 04:42, 11 September 2006 (UTC)

According to my cooperative extension, besides the thumping sound, a ripe watermelon can be distinguished by "a buttery-yellow color of the soil where the fruit rests on the ground." --Ginkgo100 talk · e@ 04:48, 11 September 2006 (UTC)


 * That thumping experiment seems nice. But if you already have you're melons ripe, what can you use as reference to whether it's dull or high pitched? --Proficient 06:19, 11 September 2006 (UTC)


 * Smell the water melon at its 'butt end'. A ripe one will have the very noticeble sweet scent (slightly alcoholic in some types). - 131.211.210.11 07:33, 11 September 2006 (UTC)

Are full moons always in the east?
Recently I was driving home at dusk and was surprised to see the sun sinking in the east. I thought I'd taken a wrong turn. It was a few minutes before I realised I was not looking at the sun sinking, but at a bright full moon rising.

This made me think - as the sun had just gone under the horizon in the west, then it was in the right position to shine full-on the moon in the east.

So are full moons always seen in the east, half-moons in the north or south, and new moons in the west?

And would some extra-clever person be able to calculate from the astronomical data I have given where I was in the world, or what date it was? 81.104.12.47 21:21, 10 September 2006 (UTC)


 * That sounds about right, if you mean where the moon is just after sunset. Seems to me that the full moon would also set in the west just before sunrise. Melchoir 21:27, 10 September 2006 (UTC)


 * Yes, why couldn't you have a full moon in the west at sunrise or a full moon in the center of the sky at midnight ? StuRat 23:12, 10 September 2006 (UTC)

Earlier this week I saw a huge full moon rise in the east and move across the sky to the west. It set in the west. This happened because the earth rotates. Half or quarter moons behave the same way. Edison 04:34, 11 September 2006 (UTC)
 * What I was going to say. See lunar cycle. A full moon is always "opposite" the sun (that is, 180° away from it in the 360° sphere of the sky), while a new moon is always very near the sun. You're more likely to see a thin crescent during the day than at night. --Ginkgo100 talk · e@ 04:51, 11 September 2006 (UTC)


 * Full moons are more usually seen in the east merely because that's the time and place where they attract attention, i.e. just after dusk and near the horizon. But then they rise and culminate around midnight and set in the west in the early morning. And no, it would not be possible to calculate your position from that information alone. The moon appears full on the same night everywhere, and always rises in a generally eastern direction (anywhere between NE and SE depending on the time of year.)--Shantavira 07:56, 11 September 2006 (UTC)


 * As Ginkgo100 observed, a moon is only truly full at the one instant when it is 180° away from the sun. When you think about that, that means that it must be midnite on that part of the Earth that is "under" the full moon. Other parts of the planet's night side will see that full moon at the same instant, but, of course, their local time will vary. For some people who are just slipping into the night side darkness, that full moon is just rising in the east. For others who are just slipping out of the night side darkness and into daylight, that full moon is just setting in the west.


 * Atlant 14:55, 13 September 2006 (UTC)

Oxford UK, September 7th? ≈Eh-Steve 19:35, 17 September 2006 (UTC)

When the moon is full, that means it's position will be in oppisition to the sun. Therefore at sunset it should be east, but at sunrise it should be west. The position in the sky is in constant motion. HighInBC 00:04, 21 September 2006 (UTC)

Chocolate allergy?
Hey all. Several years ago I noticed that eating chocolate would cause me to sneeze, usually only once or twice, within a minute or so of consumption. For a while now I've wondered what it is that is actually causing me to sneeze. I had a theory that how much I sneezed was dependant on the richness of the chocolate, but I can't say I've conclusively proven that. I assume this is an unusual case seeing as Wikipedia's allergy page makes no mention of sneezing or chocolate. Anyway, some answers please:


 * Any suggestions on what precisely within the chocolate is causing the reaction?
 * How unusual is it to a) have such a consistent mild reaction to something and b) to something as unusual (in terms of being allergic to) as chocolate?

Oh, and for the record, I am male, 17 years of age, and have eaten chocolate throughout my entire life. Hammer Raccoon 21:25, 10 September 2006 (UTC)


 * Are you allergic to chocolate? A true chocolate or cocoa allergy is rare. --Lambiam Talk  22:05, 10 September 2006 (UTC)


 * Also Photic sneeze reflex MeltBanana  22:30, 10 September 2006 (UTC)

It may not be the chocolate itself, but something else in it. Many chocolates say "processed with alkali", for example. StuRat 23:06, 10 September 2006 (UTC)


 * Indeed. You may be allergic to an ingredient like a preservative. --Proficient 06:20, 11 September 2006 (UTC)


 * But surely if I was allergic to something like a preservative then other foods that use that preservative would also cause me to sneeze. Hammer Raccoon 15:14, 11 September 2006 (UTC)
 * Is it a particular brand or type of chocolate that causes this reaction, or all chocolate? Are there different levels of severity?  User:Zoe|(talk) 17:08, 11 September 2006 (UTC)
 * The brand doesn't seem to affect it. And severity is usually the same, a couple of sneezes and that's it. Hammer Raccoon 15:55, 12 September 2006 (UTC)

Satallites in orbit
How many satallite are there in orbit at any given time? how many man-made spacecraft in total are there out there in space?


 * If you've got a few minutes, you can count all the ones being tracked on this site, though there's also few more US spy satellites not on that list.
 * Their master index appears to have 1198 entries (not counting the space shuttle and the space station). These would probably be most of the functional non-military satellites. Rmhermen 02:51, 11 September 2006 (UTC)
 * On top of that, you could have a look at our list of unmanned spacecraft by program to add some of the ones not in Earth orbit, such as the Voyager program, a few of the Pioneer program spacecraft (including one nearly 40 years old that still works and is contacted periodically), and the various others. --Robert Merkel 01:39, 11 September 2006 (UTC)
 * Pioneer 10 and 11 are both dead. But there are a number of other active missions to Mars, the Sun, Pluto, etc. A number of satellites still in orbit are dead, either in parking orbits or just not yet fallen back to Earth. (Vanguard 1, launched in 1958 but dead since 1964, is the oldest satellite still in orbit.) Rmhermen 02:40, 11 September 2006 (UTC)


 * But Pioneer 6 is probably still alive (nobody's called to check for a while). Pretty amazing gadget, that.  --Robert Merkel 04:20, 11 September 2006 (UTC)

6Q0B44E is a recently discovered satellite in earth orbit a couple of times the moon's distance out. It is suspected to be a Saturn booster from the Apollo programs which was lost in space for 30 years or so then wandered back into earth orbit circa 2001. Ironic?Edison 04:30, 11 September 2006 (UTC)

Interesting. thanx for the informations guys! i never realized the number is in 4 digits!

also, why are there so many dead ones? why doesnt the owner just blast them outwards from our solar system? it wouldnt be as harmful to polute the rest of the galaxy instead of our own solar system. plus, doesnt it get too crowded? have any two satallites ever collided?


 * Escaping from the solar system requires a lot of fuel and is therefore expensive. It's much better to force the satellite into Earth's atmosphere and have it burn up.  Also, space is huge, and a few thousand satellites aren't going to do much.  (Imagine if there were only a few thousand people on Earth's surface.  And Earth's surface is two dimensional, while satellites can move in all three dimensions.)  --Bowlhover 20:02, 12 September 2006 (UTC)

Is this how to convert moles to grams?
Say you had a mole of Iron. It'd be the same as having 56 grams of it, right? Or if you had three moles of Sulfur, it would be 96 grams. Am I correct? --GUTTERTAHAH 21:42, 10 September 2006 (UTC)


 * You are very definitely on the right track! Mass = moles x (formula mass). --G N Frykman 21:45, 10 September 2006 (UTC)


 * Well yeh your right to the level of accuracy you have given your numbers, so yeh. Philc  TECI 21:46, 10 September 2006 (UTC)


 * Ah, good. That's one thing about chemistry I won't screw up <_< Thanks a lot! --GUTTERTAHAH 21:50, 10 September 2006 (UTC)


 * And if you have a molecule instead of a monatomic element, then you need to add up the atomic weights of each atom in the molecule. So for H2O, you would add the weight of two hydrogens and one oxygen, to get the molecular weight.  This molecular weight is then multiplied by the number of moles to get the number of grams. StuRat 22:58, 10 September 2006 (UTC)

Ugh, good luck with moles. I never could understand those in Chemistry. 172.166.8.176 02:34, 11 September 2006 (UTC)


 * It's much better to deal with them in Biology. There, you can convert them to grams just by putting them on a scale. --Serie 22:31, 11 September 2006 (UTC)

Real Talking Animals
Is the possibility of animals creating their own language in the next 100,000 years possible? Besides barking or meowing etc... or the fact that some birds were trained to talk. This may be more of an opinion question unless some theories have already been created by scientists. -MF14


 * Depending on what you call a language, many animals already have one. Despite its own opening sentence, Animal language describes a few of these. Animal communication is another related, broader article. Melchoir 23:26, 10 September 2006 (UTC)


 * Yes, animals already have a "language", it's just very primitive by human standards. They can manage to tell each other when they are angry, horny, hurt, etc.  Communication within each species is the clearest, but interspecies communication is common, as well.  You generally know what your dog or cat wants, don't you ?  However, if you expect to have a discussion with your cat on the tenets of existentialism, forget it.  It's not that the communication is limited, it's that they can't understand any of those concepts, as they lack basic "symbolic logic" and any potential for abstract thought. StuRat 00:03, 11 September 2006 (UTC)


 * All sorts of things are possible over the course of 100 000 years, but while animals have means of communication, none of them (except bees) currently appear to have anything ressembling the human language faculty, which combines abstraction, symbols independent of external stimulus, and grammatical structures for building complex representations out of symbols. Scientists aren't completely sure about all the issues, but human language is not simply a more complex form of animal communication, so it's not clear there would be any reason for another species to evolve the ability. Peter Grey 02:00, 11 September 2006 (UTC)


 * A relativist's observation: human language is probably pretty primitive by, say, platypus standards. They probably think humans are pretty dumb because we cannot communicate about the things that matter to them. (And don't ask me what those are because I am only human). Platypuses learning human language is as (un)likely as humans learning platypus language. DirkvdM 08:44, 11 September 2006 (UTC)
 * I don't think that's true. A platypus is not cognatically capable of wondering if the "platypus language may possibly look primitive by human standards", and thus, is more primitive. Humans are much more likely to learn platypus language than platypi are ours, because we can observe them and create models to mimic their behavior. freshofftheufo  ΓΛĿЌ  09:12, 11 September 2006 (UTC)


 * How do you know? We're humans (a fair assumption :) ), so we cannot know how platypuses reason. We'd have to be platypuses for that. Even as a kid I always found the question "what animal would you like to be?" stupid. I'd have to be the animal to know what it is like to be that animal, but even if that were possible then I wouldn't know what it would be like to be another animal (or a human for that matter), so I still couldn't make the comparison. Your reasoning is the basis of xenophobia - they're different, therefore they are inferior. DirkvdM 09:01, 12 September 2006 (UTC)


 * I understand your argument, but I don't think you're taking a valid position. I believe that creature intelligence is directly related to logical thinking power, and a being that has the capability of thinking with a certain degree of logic is also capable of determining roughly the level of logic of a creature capable with a similar or lower level of logic than themselves. A creature with a significantly higher level of intelligence would be capable of concieving a strategy to fool others into believing that they were less intelligent as well as a reasoning for wanting to do so. I can only assume that platypi are not super-intelligent beings, though I do believe that is a fair assumption as well. freshofftheufo  ΓΛĿЌ  05:07, 15 September 2006 (UTC)


 * I'm no expert but I do spend a lot of time watching gulls and corvids and to me, it certainly seems that they have a language - a fairly complex one too. As well as the various vocalizations, there seems to be an aspect of body language used to modify the meaning of various utterances. Seriously, just watch two (non-aggressive) herring gulls communicating sometime - it's like some strange choreographed dance. --Kurt Shaped Box 14:30, 12 September 2006 (UTC)

what plant is this
The top one is a stem with some berry looking things and the bottom one is a stem that is more mature, I suppose. schyler 23:44, 10 September 2006 (UTC)


 * What part of the world did you find it in? Gary 02:35, 11 September 2006 (UTC)

North-East Texas. schyler 02:46, 11 September 2006 (UTC)


 * Are the leaves similar to grass leaves? It might be some kind of lilyturf - grasslike plants in the lily family. This one looks like it, Liriope muscari.

http://www.magnoliagardensnursery.com/productdescrip/Liriope_Big.html Gary 17:54, 11 September 2006 (UTC)

copyright, publication, volumes, and authors
How and or where do you  find the publication date and city of the encyclopedia? Where do you find the author? Where do you find the volume of the encyclopedia that you are using online? Where do you find the copyright dates?


 * Citing Wikipedia Melchoir 01:30, 11 September 2006 (UTC)