Wikipedia:Reference desk/Archives/Science/2006 September 16

=September 16=

Gull
Not really a question - but I just saw this photo and it took my breath away. How cool is this? Even the gull I raised from a couple of days old won't do this... --Kurt Shaped Box 01:00, 16 September 2006 (UTC)


 * How did you manage to mount it like that? cool! 8-)--Light current 01:04, 16 September 2006 (UTC)


 * Dunno - not my photo. You were referring to mounting the camera, right (as opposed to some form of sexual deviancy)? ;) --Kurt Shaped Box 01:18, 16 September 2006 (UTC)


 * No. Mounting of the stuffed gull of course! Is that deviant?--Light current 01:20, 16 September 2006 (UTC)


 * You sure it's stuffed? Just looks scruffy and a bit 'moulty' to me (as young gulls often are). --Kurt Shaped Box 01:23, 16 September 2006 (UTC)


 * I dont go out with young gulls, so I couldnt comment! 8-)--Light current 01:41, 16 September 2006 (UTC)


 * Looks lea-gull to me. --Kurt Shaped Box 01:53, 16 September 2006 (UTC)


 * Looks a pretty ill eagle to me!--Light current 02:33, 16 September 2006 (UTC)


 * It could just be a photoshop. Photoshoped pictures can look *really* real these days if done by an experienced photoshopper. (take a look at the photoshopped 'morphs' on this page http://www.humandescent.com/index3.shtml) Yaksha 02:02, 16 September 2006 (UTC)

Anybody notice how the bread looks like it was toasted with a clothes iron ? So we know the guy is a bachelor trying to lure young gulls into his grasp... :-) StuRat 02:42, 16 September 2006 (UTC)


 * Looks more like the gull is trying to swallow both the bread and the foolish feeders thumb.--Light current 03:56, 16 September 2006 (UTC)
 * Surely that's orange peel. How cool is this? 78%. Peter Grey 13:54, 16 September 2006 (UTC)


 * THe question I have is : who is taking the picture. If it's the person holding the bread, how the hell did s/he keep the camera so steady/ focussed etc?--Light current 20:51, 16 September 2006 (UTC)


 * That's what I was wondering too. The photographer has a whole gallery of similar pics at http://www.flickr.com/photos/elsie/sets/88049/ - some amazing stuff. Check this one out too - I've had it on my HD for ages and I can't remember where I found it: http://img133.imageshack.us/my.php?image=bethseagullhires5uzew4.jpg --Kurt Shaped Box 21:30, 16 September 2006 (UTC)


 * Looking at those pics it can only be a motor drive camera with auto focus etc.--Light current 01:00, 17 September 2006 (UTC)


 * Weird! Not the photo, but the response here.  If you throw some bits of bread to gulls on the beach, a big flock gathers.  Hold up bread, gull flys up to get it, snap picture.  If it didn't turn out well, do it again and again until you run out of bread and/or fingers.  The gulls aren't easily bored if there's food involved.  I guess the equivalent for a city-dweller would be a pigeon or squirrel eating peanuts right at your feet, where you could reach out and touch it.  --Wjbeaty 06:06, 17 September 2006 (UTC)


 * The gulls around here would never actually take food from a human's hand on the wing. They'll catch food in mid-air if you throw it to them and they'll come quite close if you place it on the ground but they are *very* careful never to enter our 'striking range'. When on the ground, they seem to calculate the distance that I'd be able to cover with a full length dive and stay just outside of that. Very wise birds - "beware the hand of man". The only one that comes closer is a gull that knows and trusts me... --Kurt Shaped Box 06:39, 17 September 2006 (UTC)


 * Photographing birds on the wing is very difficult, even at a distance. Imagine getting a good shot at a short distance like that. But photographing gulls like that under windy conditions (such as on a boat or a cliff) isn't too hard. They just hang in the air, inching closer to the person holding the bread.
 * Kurt (or should I call you 'Box'?), your gulls are on the ground and maybe that is too vulnerable a positiom for them. DirkvdM 07:27, 17 September 2006 (UTC)


 * Gulls are the masters of the updraft - it's like they're just floating there without any effort whatsoever. Forwards, backwards, sideways, they can just sort of 'slide' around in the air without flapping their wings at all (if you look closely, they do it with tiny flicks of the 'wrist'). On a hot summer's day, they love to ride the thermals and go so high as to be tiny dots in the sky. Then they glide slowly down. Thinking about it, in my garden, with nothing to catch a ride on, they'd have to swoop, dive and pull up at the last moment to take food from my hand - which is probably a pretty tricky manoeuvre for the sake of a piece of bread... --Kurt Shaped Box 12:39, 17 September 2006 (UTC)

Onions going green
There's a way to preserve onions that involves peeling the onions, and then leaving them in a jar filled with pure vinegar (normal vinegar, not white vinegar).

The vinegar soaks into the onions, and the onions are ready to eat after about a year. At the end, the onion pieces turn black (obviously due to the black color of the vinegar that gets soaked in.) After a few month, the onion pieces started turning black. However, i noticed many of them also turned green before going to black. Not like a dull green, but a bright and almost flourscent green. They'd stay green for a few weeks before starting to turn black also.

And before anyone tells me the onions have gone mouldy - i can assure you that's not the case. They're supposed to turn green. When preserving onions in vinegar, it's normal for them to start turning green.

I can't quite figure out why, no one really knows...and i'm having a bit of a hard time trying to get intelligent results by googling keywords like "green onions" Yaksha 02:02, 16 September 2006 (UTC)


 * Try searching under pickled onions. Unfortunately, our article on them is just a stub. StuRat 02:36, 16 September 2006 (UTC)


 * Garlic I've pickled has gone blue. The main changes a chemist would expect would be due to the acid of the vinegar causing changes or maybe something to do with metal ions bonding / breaking free from / swapping with different metal ions on organic molecules. Have a look at pH, denatured, chelate, chlorophyll, and colour for some background reading. Rentwa 07:21, 16 September 2006 (UTC)


 * Yeah..i know it happens to garlic too. I've seen garlic turn green when preserved in vinegar too. I pretty much guessed it was due to the acid in the vinegar and all, i'm a chem student myself. I had hoped someone here would be able to give a precise answer about exactly what in the onion did what to produce what product that caused the green-ness. thanks anyway Yaksha 12:05, 16 September 2006 (UTC)


 * If you're a chem student you can prepare various extracts and put them in a spectrometer :) . Rentwa 07:20, 17 September 2006 (UTC)

How to Build a Catapult
My sister needs to build a catapult for physics class. For her project, she needs to build a catapult that will be able to launch a tennis ball sufficently farther than the competition (her other classmates). Interestingly, grades will be determined by one's rank in distance compared to the competition. She needs to help with concepts and such, to keep this safe from that homework rule. :p

Here are the main points and rules:

Size restrictions: The maximum size of the base is 0.75 meters by 0.5 meters.

The maximum size of the movable rigid throwing arm cannot exceed .5m.

There must be a safety switch to ensure the mechanism can be fired from 2 meters away.

There are no weight restrictions. (This seems pretty important and useful.)

Any materials can be used.

Here are some questions:

What is a good place to start at when building the catapult?

What materials would be best for such a catapult? (springs, etc)

What are some sources (websites) that provide detailed instructions on creating a catapult that maximizes distance?

What are some general rules to follow?

And lastly, what are some good tips that can give the highest opportunity to have the best distance?

The key question that she wants to know is what is the best way to build a catapult that will allow her to win. :)

Please tell me if you have questions. Hopefully there are loopholes in the project that can be exploited. :P

--Proficient 03:39, 16 September 2006 (UTC)


 * I don't see a rule prohibiting tennis ball launchers, baseball launchers, nor any design like them. Also, backspin is a good thing.  A friend built a fixed-arm catapult with approximately these dimensions that would through tetrahedral packs of four tennis balls ~300 meters (of course, the arm tended to bend slightly on these maxed-out throws).  -- Fuzzyeric 03:58, 16 September 2006 (UTC)


 * Yes but these are not catapults and may be disqualified. I suggest following the Roman army design that uses torsion springs made of taut rope or sinew to store the energy. Were they callled ballistas?--Light current 04:05, 16 September 2006 (UTC)

I reckon one of these 2 babes may do the trick!--Light current 04:17, 16 September 2006 (UTC)

Ahh but heres the site you want --Light current 05:00, 16 September 2006 (UTC)


 * I would use bungee cords for the energy source. You can buy them at many stores, typically in the hardware/automotive section.  Use a peg to hold the throwing arm in place, then add the bungee cords one at a time (you will need to have eyelets on the throwing arm for the bungee cord hooks, and eyelets on the base for the other end of the bungee cords).  Make sure the base is very heavy, so it won't tip over when you pull the lubricated peg out with a rope from several feet away.  You should have a "stop" that assures the object is launched at a 45 degree angle for max distance, this will take some testing.  StuRat 06:10, 16 September 2006 (UTC)


 * Here is a rough sketch:

+-+ |S| \ |T|  \BUNGEE CORDS |O|    \ |P|      \  BALL +-+--ARM---+--+ +-+--+ | HEAVY BASE | ++


 * StuRat 06:27, 16 September 2006 (UTC)


 * Yeah you wouldnt want to jerk your dog would you? See bungee cord--Light current 06:15, 16 September 2006 (UTC)

Keep in mind that the more bungee cords you add, the harder it will be to pull the throwing arm down to the ready-to-fire position. One thought is to buy a boat trailer winch (the manual hand-crank kind) at a hardware store, and use it for cocking the firing arm. I bought one a few years ago for a project, and it was pretty inexpensive. Speaking of cost, though, what's your sister's budget? I suspect that every other student in the class is also turning to the internet, and researching old Roman catapults and stuff, and will come up with the same basic design. Want something different, and more dangerous? Use the power of compressed air for firing the thing. A big accumulator (air tank), some large-diameter hoses and a poppet valve, and a big pancake cylinder will generate way more force than a few bungee cords. It'll also make an exciting, loud noise and scare the crap out of the competition. It may be beyond your sister's technical abilities though... is she handy with tools? Does she have a MIG welder or know someone who does? --192.168.1.1 8:33 16 September (PST)


 * My instructions are to attach one bungee cord at a time, while the throwing arm is already in the firing position. Thus, you can apply maybe a dozen bungee cords, each stretched to the maximum, for a great deal of total force. StuRat 01:29, 18 September 2006 (UTC)


 * OMGLOL MIG Welder!! THis girls probably in primary school!(and probably doesnt understand the meaning of the term welding) I think Stu's idea is probably the most practical for a young girl.--Light current 16:49, 16 September 2006 (UTC)


 * Well, she wants to win, doesn't she? :)  I was going to ask what grade she was in, but forgot... I can see a high-school student maybe having access to one (a neighbor, a friend in shop class... )  A third-grader, though, probably not.  Anyway, my competitive streak came out (and my innate tinkerer).  Can I build this for her?  We won't tell anyone!  But if she wins, I get to share the prize.  --192.168.1.1 11:03 16 September (PST)


 * She is a junior in high school (physics). I will tell her of these suggestions. I thank each one of you. Please feel free to add more comments and such. --Proficient 19:15, 16 September 2006 (UTC)


 * What scares me about this is that an unlimited amount of stored energy can be put into the device. With no material or weight limit, it could be powered by a piston driven by high pressure compressed air, with a pilot valve manually triggered which opens the large main air valve very quickly. A high voltage electrical circuit breaker in a substation uses such technology. Or it could be powered by a coil spring or by a torsion spring, also like used in substation circuit breakers and automatic throwover gear. Either the compressed air or the spring could have enough energy to lift a car off the ground, so the transfer of that energy to a tennis ball could result in perhaps lethal speed at launch, which would decay rapidly due to air resistance. One could build a catapult, the firing arm of which was capable of knocking off the head of anyone in its way if it fired inadvertently. If I wanted to win this contest at all costs and regardless of risks, I would get a spring such as is used on a car, and use a ratchet and windlass, or perhaps a car hydraulic jack, to cock it. Think a classic crossbow made into a catapult. If it came apart or fired prematurely, it could sever limbs. It would be apt to break and throw deadly parts in various directions to considerable distanced. The firing arm would be low mass to allow max acceleration, but strong enough to stand the acceleration and deceleration. A damping device would be needed to absorb the impact when the firing arm stops. The whole device would tend to jump in the air when fired, so I would design for low center of gravity with a massive baseplate. When the trigger released the firing arm, which would probably require a clever trigger mechanism to avoid binding, the firing arm would rotate from its rest position to, say, a 45 degree angle or something between 45 and 90, selected to achieve maximize range. It would stop by hitting the arresting device and the tennis ball would continue. The limiting launch velocity would be that which breaks the tennis ball or the mechanism. Design conservatively with a large safety margin. I would have written the rules to limit weight and materials to avoid the hazards inherent in this very open statement of rules. As always, these comments are purely theoretical: don't try this at home. Edison 19:41, 16 September 2006 (UTC)


 * You could also take some pointers from the recurve bow. That's basically the thing that made mongol bows so dangerous. Basically, if you just use one half of it you get a catapult, right? Btw, I once saw a video of atrebuchet flinging a car into the air. It landed tens of metres away. Pretty potent stuff! DirkvdM 07:41, 17 September 2006 (UTC)


 * Trebuchets don't scale linearly: throwing power increases somewhere between the square and the cube of size, so while a large trebuchet is more powerful than a large catapult, a small catapult is more powerful than a small trebuchet.


 * Back to the original competition: the rules limit the rigid part of the throwing arm to half a meter, but there's no mention on a limit on a sling. All medaeval throwing weapons had a sling on the end of the arm to increase range.  Calibrating the release hook for the sling is something of an art, but if you get it right, you can easily double the range of your catapult. --Serie 19:38, 19 September 2006 (UTC)

On the subject of materials, I recommend something like cast iron (with possibly lead added) for the base and aluminum for the throwing arm. For the arm, you want something light and stiff, emphasis on light so it can accelerate quickly. Dipics 14:37, 22 September 2006 (UTC)

Effects of using spent perlite as soil conditioner to improve yield of corn
one of the by products in the manufacture of carrageenan is perlite - predominantly Si02 used in the filtration process. do you have technical papers citing the benefits of usig perlite as soil conditioner to improve yeild of corn? we generate about 3-4 mt/day and it will also help transform the waste into agricultural purposes and help the local farmers.

json of the philippines


 * Probably best to contact the Perlite association --Light current 04:58, 16 September 2006 (UTC)


 * Perlite is used to lighten (improve drainage, aeration etc) heavy soils. I'm sure it would help agriculturally, although I think most of the data available will be from horticultural sources, try searching for perlite as a compost additive / ingredient for more info. It may be contaminated (depending on the details of your process). If the contamination is with organic matter it may encourage excessive microbial growth, which may be harmful. Rentwa 07:38, 16 September 2006 (UTC)

Black Rain
What was the black rain that happened after the Hiroshima blast? --Shanedidona 04:20, 16 September 2006 (UTC)


 * Probably nuclear fallout: radioactive fission products and unreacted fuel from the bomb. —Keenan Pepper 04:35, 16 September 2006 (UTC)
 * (edit conflict) A combination of water, ash and radioactive fallout such as isotopes of uranium, caesium, and lead. ---Sluzzelin 04:40, 16 September 2006 (UTC)


 * And probably other dust and debris which was sucked up into the mushroom cloud. --Fastfission 17:23, 16 September 2006 (UTC)


 * And anything thing that was vaporised in the original blast recondensing. Philc TECI 17:27, 16 September 2006 (UTC)


 * It is very well described in the horrific Black Rain by Ibuse Masuji: Secker & Warburg, London 1971 -- Puffball 07:40, 22 September 2006 (UTC)

we have heard of 2, 4, 8 , 16 , 32 and 64 bit processors .why not there any processor that is of odd bit number?
is there any processors that are of 1,3,5,7 etc. bits or 6,12,24,48 etc.bits? why a 64 bit processor is better than 32 bit processor and how ?


 * You should probably try Computing rather than Science, but let me just say there are several different things "#-bit" could refer to: the number of bits in a byte, the number of bits in a memory address, the width of the computer bus... —Keenan Pepper 04:39, 16 September 2006 (UTC)


 * The GE-600 series (a.k.a. "Honeywell 6000 series") and the PDP-10 were 36-bit computers. The Ge-600 also had 6- and 9-bit addressables (which can make the second definition of byte difficult to apply).  The CDC 6000 series used 60-bit words.  The IBM 7030 had variable length bytes (1-8 bits).  During the relevant time period, bytes can in all kinds of sizes, leading to the use of the phrasing n-bit-byte ("8-bit-byte").
 * The Motorola 68000 was degenerate in that there was no address pin zero, so the minimal actually addressable was 16-bits although the pointers had 8-bit resolution. (Dereferencing an odd address threw an exception.)
 * To answer your 32-/64-bit question, see 64-bit computers. -- Fuzzyeric 05:26, 16 September 2006 (UTC)


 * See Category:Data unit. There are certainly quite a few computer architectures which use data sizes which are not a power of two bits, but 31-bit is the only one I'm aware of which isn't an even number.


 * The main reason why a 64-bit processor is "better" than a 32-bit one is that it can address (or "use") more memory. A 32-bit processor can only use 4 GB of memory unless certain work-arounds are used; a 64-bit one can use 4 billion times as much. For current personal computers, there isn't much demand for more than 4 GB, but for servers and some scientific applications, the extra memory is very useful.- gadfium 05:20, 16 September 2006 (UTC)


 * The Electrologica X1 had a 27-bit word length. --Lambiam Talk 11:54, 16 September 2006 (UTC)
 * Actually it's not just about more then 4gb. Given the design of many OSes, 64 bit OSes (and therefore 64 bit processors) are useful if your using more memory then a certain amount, usually 2 gb. Also, there are AFAIK certain other advantages in terms of optimisation for certain algorythms. For example SHA256 and SHA512 work better with 64 bit computers. Nil Einne 23:02, 27 September 2006 (UTC)

help me to know more about the colour of the urine
I want to know what are the unnormal clours of the human 's urine ? Can it be green? does it's colour depend on what has been drunk?


 * Yes, it can be green, and it does depend on what you eat and drink, but it's not as simple as always being the same color as what you eat or drink. It can also be clear if you drink a lot of water.  Yellow, of course, is normal.  Red or brown indicates blood in the urine, and merits a visit to the doctor (hopefully it's just a bladder injection and some antibiotics will fix you right up). StuRat 06:40, 16 September 2006 (UTC)


 * Normal urine is a pale yellow: that color is a result of the presence of urochrome. Dilute urine, caused by increased fluid intake, can be colorless; concentrated urine, caused by decreased fluid intake, can be dark yellow
 * There are two relatively common abnormal colors that correspond with physical disorders. Dark brown ("tea-colored" or "Coca-Cola") urine can indicate a problem metabolizing bile in the liver - if this is the case it can be accompanied by a yellowing of the skin and eyes (jaundice), and by pale feces. Red or pinkish urine can indicate the presence of blood in the urine, which can be the result of urological probem.
 * Also, a "cloudy" urine may indicate an infection.:There are less common abnormal colors as well. Some of them are related to foods, vitamins or medications such as beets, B vitamins, pyridium, or rifampin
 * Green urine is very unusual, but can result from artificial colors such as methylene blue, or pigments produced by certain microorganisms that cause urinary tract infections.
 * Obviously, if anyone has an abnormally colored urine that isn't linked to an obvious specific cause, they should talk to their doctor about it. - Nunh-huh 06:43, 16 September 2006 (UTC)


 * It can also go green from an overdose of B-Vitamins. B00P 10:33, 16 September 2006 (UTC)


 * Porphyria (the madness of King George) can cause purple-pink urine, but most bizarely of all, the flourescent microbes found in seawater can give sea travellers glow-in-the-dark urine even if the sea water is thoroughly treated before drinking. smurrayinch e ster(User), (Talk) 21:22, 16 September 2006 (UTC)


 * Hmm. Handy for pissing in the dark.--Light current 01:02, 17 September 2006 (UTC)


 * Your name would take on a whole new meaning. :) DirkvdM 07:53, 17 September 2006 (UTC)

Asparagus will often cause urine to be green colored. Check this link for all urine color changes, and also this page, which says that other foods, as well as some medicines, including Risanpin, an antibiotic, will cause urine to be green (or blue). Blank Verse 05:18, 17 September 2006 (UTC)


 * I recently saw a documentary on the possibility of missions to Mars and the preservation of water. Of course that meant distilling the urine for reuse. The leftover concentrated urine was gathered in a transparent (!) tank and looked very dark yellow of course, but with a definite reddish hue to it. Is that blood or what? DirkvdM 07:53, 17 September 2006 (UTC)


 * Urochrome--Light current 20:01, 17 September 2006 (UTC)

lexapro
is blurred vision a side effect of taking this medication? john
 * http://www.drugs.com/lexapro.html http://www.lexapro.com  --GangofOne 06:49, 16 September 2006 (UTC)


 * Any strange effects (such as yours) whilst taking your meds should be reported to the doctor quickly.--Light current 09:06, 16 September 2006 (UTC)

Luminosity
I added the following to Barnard's star yesterday: It has a "visual luminosity just 4/10000 of solar, corresponding to a bolometric or absolute luminosity of 3.46/1000." This is based on this and this paper within it. But I'm uncertain if I have this right, as it suggests the first figure is a relative value and the second absolute, while our page on solar luminosity mentions no distinction. Also don't no why there's an order of magnitude difference, though I think I'm reading it write. Marskell 07:15, 16 September 2006 (UTC)


 * Dont worry. Someone will correct it if its wrong.--Light current 09:08, 16 September 2006 (UTC)


 * LOL. I don't like to edit that way. I'd rather know I'm right or not before I add the point; call it amateur responsibility. Marskell 09:31, 16 September 2006 (UTC)

So do I but its not always possible. Just edit in good faith OR put a question on the respective talk page pending your edit (or even afterward)--Light current 14:31, 16 September 2006 (UTC)


 * The visual luminosity is the total amount of visible light output from a star. The bolometric luminosity (which, I believe, is what astronomers usually talk about when discussing luminosity) is the total radiated energy output: visible light, ultraviolet, x-rays, infrared, radio, etc.


 * Barnard's star is smaller and cooler than the Sun, which means that its light output is redder than the Sun's and that it radiates less energy per unit of surface area. Also, a larger fraction of that output is down in the infrared, rather than visible light.  So the total energy output of Barnard's star is about 0.346% that of the Sun.  Because a larger portion of that output is in the infrared, Barnard's star's visual luminosity is even lower&mdash;0.04% that of the Sun. TenOfAllTrades(talk) 17:37, 16 September 2006 (UTC)


 * OK, thanks. I assumed something like this, but it often doesn't seem to be made clear when detailing luminosity. When luminosity states "In astronomy, luminosity is the amount of energy a body radiates per unit time" it makes no mention of the distinction, which is fine I suppose, insofar as the generic term is taken for absolute output. But the characteristics in star tables on our pages use the other figure and say "luminosity", not "visual luminosity", which strikes me as an error. Marskell 19:47, 17 September 2006 (UTC)

Weird strings during nuclear explosions
What are those things that rise or fall from/to the ground during some nuclear explosions? White trails of smoke, they look like. 81.93.102.3 11:31, 16 September 2006 (UTC)


 * Do you mean mushroom clouds ? StuRat 11:36, 16 September 2006 (UTC)


 * Not at all, but you can very clearly see them in http://en.wikipedia.org/wiki/Image:Mushroom_cloud_sequence.jpg - WHITE TRAILS. :) 81.93.102.3 11:54, 16 September 2006 (UTC)


 * If memory serves, they are rocket trails. Measuring gauges of some sort would be shot up on rockets just before the explosion.--Rallette 12:03, 16 September 2006 (UTC)


 * That seems to be correct; see Effects of nuclear explosions. (But see also Rope trick effect, which can also produce curious lines in pictures of nuclear tests.)  —Ilmari Karonen (talk) 13:55, 16 September 2006 (UTC)


 * Yeah, they are smoke trails from rockets that go off right before the blast. You can measure blast effects with them which would otherwise not appear on film in a quantitatively measureable fashion (like the shock wave and changes in air pressure). --Fastfission 17:21, 16 September 2006 (UTC)


 * If this is about the vertical striations each side of the cloud, I used to think this was an electrical discharge phenomenon due to the intense emp generated by the blast but looking at the photos linked to, it appears I was wrong.--Light current 01:21, 17 September 2006 (UTC)


 * You are all wrong, if you are talking about, as I suspect, pictures of early "ground burst" tests which sometimes show bright more less diagonal lines. In such pictures, you can sometimes see the vaporized remnants of cables which had been used to anchor the tower holding the bomb, or to anchor (un-manned!) blimps which held scientific instruments.  This is discussed in Richard Rhodes, The Making of the Atomic Bomb.


 * It is true that some pictures also show electrical discharges related to atmospheric disturbances resulting from an nuclear explosion; these tend to look like lightning flashes, not straight line segments. ---CH 22:36, 19 September 2006 (UTC)


 * Sorry, just noticed that someone already linked to Rope trick effect. I think the mention of rockets is a third possible correct explanation.  Looks like you would have to provide a link to a specific picture.---CH 22:40, 19 September 2006 (UTC)

name of species - or common name
resembles - to me at least - a snail, is very large - maybe 10" across, lives on land, only seen photo long ago, remember it being quite colorful
 * I am in no way a snail expert, but if you can find a photo, it would help those here that do have experience with zoology. --Russoc4 14:51, 16 September 2006 (UTC)
 * Maybe a flatworm or land planarian? Reference desk archive/Science/May 2006 --Kjoonlee 16:04, 16 September 2006 (UTC)
 * Sounds perhaps like one of the West Indian land snails famously studied by Stephen Jay Gould. Possibly either the genus Cerion or Poecilozonites. They don't have specific Wikipedia articles, but you can look at Bermuda Land Snail or try a Google search (e.g., cerion snail). --jjron 16:35, 17 September 2006 (UTC)

Thanks - ?but no thanks? - someone is not paying attention. I tried to be concise and clear. "RESEMBLING A SNAIL" - i.e. it has a LARGE shell, definitely not a worm or planarian. "VERY LARGE" - not almost microscopic. "LAND" animal - not aquatic. Definitely not a tiny West Indian snail. Much larger than the Giant African Land Snail. And no, I do not have a picture or name or anything - just a vague memory.

On Glass Cleaners, Ammonia.
In Windex brand cleaner and other glass cleaners, is there ammonia in solution with water or is it the ammonium ion in solution from ammonia containting compounds? --Russoc4 14:48, 16 September 2006 (UTC)


 * See Windex. Other glass cleaners are not necessarily the same, for example, some are based on white spirit.--Shantavira 17:39, 16 September 2006 (UTC)


 * So is ammonia used as a glass cleaner or not? If I just wanted to read a static answer in the article, I wouldn't be here on the ref desk. I'm looking for a more dynamic answer that doesn't just aimlessly redirect me to an article.--Russoc4 18:27, 16 September 2006 (UTC)
 * It says in the article that it is ammonia. --liquidGhoul 02:49, 17 September 2006 (UTC)

Ammonia is a very weak base, and so a solution of it would not normally contain very much of the ammonium ion. Further evidence is that ammonia smells, and the ammonium ion does not. Smell the Windex! --G N Frykman 20:55, 16 September 2006 (UTC)
 * Thank you Frykman. You've been most helpful. --Russoc4 21:09, 16 September 2006 (UTC)

Cancer stats
Where would I find a list of top incidents of cancers (prostate and breast) per county in the U.S.?


 * By county, I'm not sure, but the American Cancer Society has a load of US cancer statistics by state at the very least. I have seen by-county maps out there before (they are sometimes quite remarkable) but I don't know offhand where they are. --Fastfission 17:29, 16 September 2006 (UTC)

Psychopathy prevalence
I am taking a criminology course in college and recently learned from the professor that statistics show psychopathy is more prevalent in the united states than in japan and other asian countries (controlled for population). I asked the professor why this was and the theory he came up with is that it could be genetically less prevalent in ethnic asians or that a more individualistic culture might be correlated with a higher incidence of psychopathy. Is there any statistical evidence for or against this theory (possibly the percentage of asian peoples diagnosed as psychopaths in the US)? Thank you very much for your time, any evidence would really liven up class discussions! -Timothy

Comment: I would call that hypothesis or conjecture instead of theory.


 * I don't know, though you might be interested in reading race and intelligence, but first check out the maps at Race Differences in Intelligence.--Shantavira 18:53, 16 September 2006 (UTC)


 * One potential confound to researching genetic differences among ethnic groups is that even in one country, different ethnic groups generally have cultural differences. Most clinical psychologists would point to a cultural explanation rather than a genetic one to explain differences among ethnic groups; this approach even has a name -- the sociocultural model. Also note it is simplistic to say that the U.S. has a higher prevalence of psychopathology; this may be true overall (I don't have it in front of me), but different disorders have different prevalences around the world. Schizophrenia has similar rates in all cultures. Also, there is a cultural component to the symptoms of some diseases -- for example, with major depression -- and some disorders are peculiar to certain cultures. --Ginkgo100 talk · e@ 19:44, 16 September 2006 (UTC)


 * Whoa, I just realized I mistook the work "psychopathy" for "psychopathology". Very different things! Psychopathy, of course, is aka antisocial personality disorder, one of many types of psychopathology (mental disorders). --Ginkgo100 talk · e@ 00:41, 18 September 2006 (UTC)

I suspect that the incidence of psychopathy is either overreported in the US (say by criminal lawyers hoping for leniency) or underreported in Japan (possibly due to the shame associated with such a diagnosis). StuRat 23:44, 16 September 2006 (UTC)

Two words: ascertainment bias. What an astonishing question. There are enormous cultural differences between the two societies. It is hard to think of a more culture-dependent imputed category than "psychopathology", which is originally a European concept wholeheartedly adopted and elaborated in North America. How could anyone imagine that the classification and ascertainment procedures would be the same in the two countries. Find another professor if he really believes that. alteripse 00:11, 17 September 2006 (UTC)
 * There is an essential difference between psychopathology – the study of various forms of mental illness – and psychopathy – a presumed personality disorder characterized by the inability to experience compassion or remorse. I doubt that the latter concept is originally European. --Lambiam Talk 20:00, 17 September 2006 (UTC)
 * Thanks for pointing out that I wrote psychopathology when I meant psychopathy. The former is a very broad category roughly equivalent to "mental illness", while the concept of psychopathy (and the more common term psychopath) derives from European and American psychiatry. See Werlinder H (1978) Psychopathy: A History of the Concepts. Uppsala: Almqvist and Wiksell if you dont believe me. However, my answer does apply to psychopathy not psychopathology. alteripse 02:36, 18 September 2006 (UTC)

Thanks for the information guys. And no thanks for the completely unhelpful trolling alteripse. -Timothy
 * If you dont think my answer was a direct relevant answer to your question, you and your professor are well-matched. alteripse 17:25, 17 September 2006 (UTC)


 * Geez, Timothy. alteripse is the only self-identified medical professional who responded to your question, and s/he said exactly what I was going to say (but didn't because it'd already been said). Maybe some of it was strongly worded, but it wasn't trolling, IMO. No need to take offence for a WP editor casting aspersions on your prof. Anchoress 17:39, 17 September 2006 (UTC)

Project management
I would like to know of existing or recent case studies or experiences from community based projects in some Developing Nations with respect to methodologies in project management and evaluation. Preferably in the building/construction area.

Micro-climate in Nigerian houses
Please help me with information on housetypes of the pre-colonial Nigeria and how the various types of architecture of the three major geo-political zones (north, southeast and southwest)as well as the materials used helped in creating a tolerable micro-climate within the building.
 * Maybe some of these links can help you: Encyclopedia Brittanica African architecture, various articles by Uche Isichei, Article by Adesoji Jiboye in Anthropologist, 6(3): 169-174 (2004) pdf file! (html version).---Sluzzelin 05:56, 18 September 2006 (UTC)

ABS with a manual transmission?
It seems that I can't get an Anti-lock braking system (ABS) on a Toyota with a manual transmission. Anyone know why this might be? Is ABS avilable only on any cars with an automatic? I amazingly can't find much on this. -Ravedave (help name my baby) 20:15, 16 September 2006 (UTC)


 * There's no physical reason why you can't have ABS on a manual; most cars in the UK are manual and it's legally mandated that all new cars are fitted with ABS. I don't know why you can't get that combination from your dealer. --Yummifruitbat 20:35, 16 September 2006 (UTC)


 * I don't know either, because the lack of ABS means no stability control either. I wonder if there is something with the manual that costs more. -Ravedave (help name my baby) 20:38, 16 September 2006 (UTC)


 * I thought ABS was mandated in the US. Are you sure you aren't thinking of ASR or ESC? --Russoc4 21:12, 16 September 2006 (UTC)

To cut production costs, manufacturers like to limit the number of available combinations of options. For example, power windows and power locks almost always come together, even though there is no technical reason preventing one from being offered alone. StuRat 23:31, 16 September 2006 (UTC)


 * I have a 2000 Dodge Dakota pickup truck with manual transmission and 4-wheel ABS, so I know for a fact there is no incompatibility between a manual transmission and ABS. --Gerry Ashton 03:59, 17 September 2006 (UTC)
 * I wonder if it takes 2 Master cylinders on manuals.-Ravedave (help name my baby) 04:12, 17 September 2006 (UTC)


 * The service manual says the same master cylinder is the same for all 2000 Dodge Dakota models. --Gerry Ashton 04:18, 17 September 2006 (UTC)


 * Lack of ABS does not mean "no stability or control." See the section on "effectiveness." --Smack (talk) 17:46, 17 September 2006 (UTC)


 * here in Australia, Toyota supplies manuals with ABS.see www.toyota.com.au Downunda 23:31, 17 September 2006 (UTC)
 * Toyota is playing games here, I have cars from 1992, 1997, and 2003, all have manual transmissions and ABS (none are Toyotas). And to Smack, what he meant by 'no stability control' was that no ABS system usually means the car has no way to meter the wheels for electronic traction control.  To Ravedave, cars require a master cylinder for brakes whether there is ABS or not, the ABS mechanism is actually often far away from the pedal mechanism, so they would have to offer manual transmissions only on cars without brakes... hmmmm...  --Jmeden2000 15:04, 18 September 2006 (UTC)

histologia
CualSeptember 17September 17on las diferencias entre mastocitos y celulas cebadas? Son identicos. Celulas cebadas (literally "barley cells", mast cells in English) and mastocitos (mastocytes) are one and the same thing. ---Sluzzelin 22:33, 16 September 2006 (UTC)
 * What are the differences between what and what? Esto es el Wikipedia inglés. --Nebular110 21:51, 16 September 2006 (UTC)

¿Ha visto Ud. es:mastocito? Yo leo ...también son llamadas células cebadas. Hyenaste (tell) 01:51, 17 September 2006 (UTC)


 * You can ask a trick question in Spanish at the English science ref desk, mutilate it by replacing a letter with the date (twice) and still get an answer. Is that cool or what? DirkvdM 08:36, 17 September 2006 (UTC)