March 7

Why do White Castles disagree with so many people?

Hello. I personally love White Castle, but all I hear from everybody is how they give everybody gas and make everybody feel awful and things like that. I'm asking this cause I've never had a problem with them before, but today I had 8 of them for lunch and I feel absolutely awful. Why does it seem like they cause this reaction more than any other fast food place? NIRVANA2764 02:49, 7 March 2007 (UTC)[reply]

I'm not sure (don't have any references to cite about any of this), but they're pretty greasy, aren't they? Some people can't tolerate much grease at all. Others of us, we can usually eat lots of it comfortably, but sometimes, depending on metabolic cycles or mood, or what else there is in the stomach, or whatever, too much grease is definitely gross. —Steve Summit (talk) 04:05, 7 March 2007 (UTC)[reply]

Here's the nutrition info for a single White Castle hamburger (I had to go to a third party site, since White Castle's own site has the nutrition info conveniently "under construction"): [1]. I'm assuming you mean you had 8 regular single hamburgers. In this case, you had 56% of your daily calories, 64% of your daily fiber, 88% of your daily fat, 120% of your daily saturated fat, 96% of your daily protein allowance, and 48% of your daily sodium allowance. This is a lot to digest at once, especially the saturated fat. The onions also really do me in. While a hamburger is definitely healthier than a double cheeseburger [2], this benefit disappears when you eat eight of them. What makes the WC hamburger "junk food" is that it doesn't fill you up and you need to eat eight to feel full. You would have to eat about 14 WC hamburgers to get your daily calorie requirements, at which point you would have eaten 210% of your daily saturated fat allowance. And, if you are like many people who eat twice their daily calorie requirements, that would give you 28 WC hamburgers and a whopping 420% of your daily saturated fat allowance. And, despite all that bad fat, you still would be lacking many of the vitamins, minerals, amino acids, etc., your body needs. StuRat 12:27, 7 March 2007 (UTC)[reply]

well my wife said she saw how white castle burgers are made. they say they steam them and cook them from one side and dont bother to flip it. let me just say that is very nasty XD as one side remains a bit raw. if you look closly to your burger you will see 4 little imprints on one side only that is where they steam them. the other side is just left to cook that way. one side is well done while the other is not so well done which gives you problems with your stomich =) but i got to admit those little burgers are very tasty!Maverick423 14:24, 7 March 2007 (UTC)[reply]

I am pretty sure they don't start out with 'raw' material in the first place, i think those little postage stamps are actually soybeans and sawdust, with some fryer grease mixed in to give it a beefy taste. So in terms of done-ness, I really don't think you have anything to worry about. --66.195.232.121 15:10, 7 March 2007 (UTC)[reply]

plasma to electricity

This phenomenon requires energy, in the form of applied high voltage, to get started, but probably cannot be used as a supply of energy. Nimur

is there a way to turn plasma to electricity or to create plasma in a circuit between 2 electrodes and than mix in a third source energie (plasma ,light or other)?

Not sure what you mean. A plasma is an electrically neutral collection of charged particles. In that sense it is more like a conductor with interesting properties associated with drift and diffusion current and the large difference in velocities between electrons and ions. Inserting an electrode into a plasma will charge it up negatively due the larger amount of electrons that will impact it per second (due to velocity differences). equilibrium will be reached at some voltage that allows for equal impacts. This is very similiar to a diode. --Tbeatty 04:27, 7 March 2007 (UTC)[reply]

im not talking about puting an alectrode in the plasma, i mean creating flow of plasma between a positive an a negative electrode put in a closed circut and than mixing another kind of plasma in the flow for it to go trough the electrodes along with the current , if the system is strong enough the idea would be to extract energy from lightning or maybe from sunlight if it is compatible , would this be possible? clockwork fromage

No. --Tbeatty 05:08, 7 March 2007 (UTC)[reply]

is it that far fetched?

It looks like some have tried to extract energy from a moving plasma in a magentic field: from magnetohydrodynamics:

MHD power generation fueled by potassium-seeded coal combustion gas showed potential for more efficient energy conversion (the absence of solid moving parts allows operation at higher temperatures), but failed due to cost prohibitive technical difficulties. ref=# ^ [3] GB 05:48, 7 March 2007 (UTC)[reply]

so basically it would be possible to capture lightning this way but extremely hard and if magnetic reconnection occurred it would make a huge explosion , correct ?

Fluorescent light or neon light? I still can't decipher exactly what the original questioner means. You cannot extract energy from lightning (electric sparks) that you induce in your device; you have to supply energy to create them. Nimur 07:01, 7 March 2007 (UTC)[reply]

lightning from storms not man made , why coudnt that be considered as an alternative energie source ? clean , renewable and great potential clockwork fromage

Lightning is hard to predict and hard to collect. It doesn't offer a constant, predictable, or reliable energy source for mass power generation. -- mattb @ 2007-03-07T15:08Z

its predictable is you use lightning rods and you seed the clouds

Quntam energy compulsion cycle?

I read in an article that quantam energy compulsion is caused by the diminutive release of the particle decobodification through homosapions and large values of hydrocronic electric plasums but acourding to theoritical quantum sulfur theory almost all mast produced hydrocronic electricity is by far indeginable.Intectuell homospions such as myself find this humerous because of the inditable facts.because of that mistake I knew the rest would be "mumbo jumbo" so thats why I posted my question.Anyway my question is how does the hydrocronic Quantum theory prove that all protons have quantum energy???ALSO I think that Milad is really cool!!! —The preceding unsigned comment was added by 74.102.217.142 (talk) 04:33, 7 March 2007 (UTC).[reply]

I believe this will answer all of your questions. --BenBurch 14: 07, 7 March 2007 (UTC)

Am I missing something? Capuchin 14:32, 7 March 2007 (UTC)[reply]

About 500 mg. ;-) --BenBurch 16:55, 7 March 2007 (UTC)[reply]

membranes freely permeable to K+ (Na+?)

"if a membrane were freely permeable to K+ but impermeable to other positively charged ions, K+ ions..." continue moving until equilibrium potential (K) is reached.

why is there a constraint that it be impermeable to other positive ions? why not also include negatively charged ions?

what about the conditions if the equilibrium potential for Na were desired to be reached? should the membrane be permeable to Na+ only?

note: RMP assumed at -70mV for standard 'excitable cell'

Take a look at Reversal potential. --JWSchmidt 15:38, 7 March 2007 (UTC)[reply]

The equilibrium potential (aka reversal potential) of an ion assumes that the membrane is permeable only to that ion, and impermeable to all other ions, not just ions of the same charge. So the constraint would include both positively and negatively charged ions. To reach sodium's equilibrium potential, the membrane must be permeable to sodium only, as you said. --David Iberri (talk) 17:12, 7 March 2007 (UTC)[reply]

SHARE ME THESE IDEAS

idea#1:Does the time behave like avector? Moving with aconstant velocity, ds1=vdt1,ds2=vdt2 ds=SQR(ds1^2+ds2^2), vdt=SQR{(vdt1)^2+(vdt2)^2}, hence, dt=SQR(dt1^2+dt2^2). Moving with acceleration and velocity is zero, ds1=gt1dt1,ds1=gt2dt2, dt=SQR[{(t1/t)dt1}^2+{(t2/t)dt2}^2]. it looks like the time behaves lik avector here,but it doesn`t when, ds=ds(v)+ds(g)=vdt+gtdt.the question is why is that?

idea#2:can we use the phenomenon of MIRAGE and LOOMING to explain why the planets of the solar system rotate in one direction while venus rotates in the opposite direction???

See Retrograde_motion#Retrograde_rotation for current theory. StuRat 12:03, 7 March 2007 (UTC)[reply]

idea#3:LOGICAL OBSERVATION FUNCTION. i think it is better to redefine th concept of velocity,because v=ds/dt,it means that the derivative of (s)with respect to astraight line which is (t).now, let`s put,

v=[(ds/dt-df/dt)/SQR{1+(df/dt)^2}], f(t)= constant if (s) as avector<0, f(t)=it,i=SQR(-1) if (s) as avector>0, we will call f,the logical observation function. it helps us to understand the relativistic concepts of motion.it helps us for instance to understand and solve the twin paradox.

80.255.40.168 10:15, 7 March 2007 (UTC)ARTHER.[reply]

For one analysis see [4]. Edison 14:50, 7 March 2007 (UTC)[reply]

Edison brings up an excellent point. Nimur 20:17, 7 March 2007 (UTC)[reply]

Burglarizing snot from my nose

A while back (about two years), I recall in the news a study about nose-picking. The findings—at least those reported in the news—were that people who pick their noses are more in touch with their bodies than those who do not pick their noses. However, the article on nose-picking only mentions a bunch of risks associated with nose-picking—all of which seem highly improbable.

Getting to the point, I was wondering if anyone else had heard about the study? Was the science behind the study credible? I think this would make a nice addition to such a lovely topic. − Twas Now ( talk • contribs • e-mail ) 12:39, 7 March 2007 (UTC)[reply]

what good is digging for gold if you cant share it with the towns people! but honestly nah i havent heard of such a study. however i did hear that people that masturbate are more intouch with there bodies (gee wonder why) Maverick423 14:31, 7 March 2007 (UTC)[reply]

What makes paper sticky when damp?

At one point or another, I'm sure everyone has received a wet newspaper in the driveway. Or has stepped on a sheet of paper after taking a shower. What makes wet newsprint cling to itself so tightly? And what makes paper stick to damp skin so steadfastly? --72.202.150.92 14:30, 7 March 2007 (UTC)[reply]

well paper starts off as a goo or something like that that is dried repeatly. when its a goo it sticks alot however when it drys you can write on it and all that good stuff. that is why people use wet paper to make art works.Maverick423 14:42, 7 March 2007 (UTC)[reply]

I think Maverick is on the right track. It starts off as a thick, fibrous and gluey pulp. The addition of water probably makes the paper wet, and bothers the glue, which would make it go back towards the pulp stage of it's development? [Mαc Δαvιs] X (How's my driving?) ❖ 01:15, 8 March 2007 (UTC)[reply]

Maybe it's to do with the fact that the hydrogen bonds continue through the fibrous material. Seans Potato Business 20:44, 8 March 2007 (UTC)[reply]

Seagulls as game birds?

Why don't people shoot seagulls for food? They're big, they're fat, there's lots of them but as far as I know, people don't eat them. Considering that people shoot ducks, pheasants, pigeons, etc (all smaller birds), why not the seagulls too? --84.65.223.136 15:55, 7 March 2007 (UTC)[reply]

because they live in rural/semi-rural/populated areas, that is the same reason why people cant shoot geese >.< it would be good if we could because all the local fields and parks by me are absolutely covered in goose droppings. -maxx- 66.99.49.226 15:58, 7 March 2007 (UTC)[reply]

Local by-laws in most areas say you can't kill animals without special permits. They're also more likely to have harmful chemicals in their body, more so than birds who live in rural areas or on farms. -- Zanimum 16:27, 7 March 2007 (UTC)[reply]

And their leader, User:Kurt Shaped Box, would have them attack and wipe out mankind. StuRat 18:36, 7 March 2007 (UTC)[reply]

We actually eat very few carniverous animals in our daily diet - and there is a good reason for that. Biomagnification. Toxins in the environment are taken up at the bottom of the food chain and concentrated at each subsequent link of the chain. Seabirds are towards the top of the marine food chain - we are better off eating fish instead. SteveBaker 19:02, 7 March 2007 (UTC)[reply]

My grandmother actually dined on gull stew with her family during WWII. According to her recollections, her father once shot two black-headed gulls and brought them home for the pot (he'd eaten them himself as a child, so I guess he thought "why not?") to supplement the rations. The meat was apparently quite strong-tasting, tough, dark and stringy but it 'wasn't awful'. --Kurt Shaped Box 00:02, 8 March 2007 (UTC)[reply]

Seagulls are scavengers: they eat things like garbage and carrion. This means they pick up the flavor of whatever they eat (seagull meat, like most carnivore meat, doesn't taste very good), and they tend to pick up whatever diseases and internal parasites their food had. --Carnildo 20:15, 7 March 2007 (UTC)[reply]

Gulls are also generally very scrawny. The bulk you see is mostly feathers. --Kurt Shaped Box 23:27, 7 March 2007 (UTC)[reply]

If seaguls, then why not pidgeons, foxes, cats, &c :] HS7 19:20, 8 March 2007 (UTC)[reply]

Pigeons are frequently eaten, although they're not the feathered rats we see in urban areas. Corvus cornix 22:29, 8 March 2007 (UTC)[reply]

Birds have very little fat on them, with up to half of their weight being made up of muscles, mostly in the wings, and the rest divided roughly equally between feathers and bones :) HS7 19:53, 8 March 2007 (UTC)[reply]

AFAIK, most of a bird's muscle mass is in the breast - those muscles are the ones that power flight, not the ones in the wings (take the feathers off the wings themselves and there's not much there). Birds that do a lot of walking/running also have muscular legs (i.e. the 'drumstick'). --Kurt Shaped Box 20:32, 8 March 2007 (UTC)[reply]

sorry, that should have been for the wings :( HS7 20:19, 9 March 2007 (UTC)[reply]

Oil sands vs. Tar sands

A reporter has asked why we use tar sands as the title for the article, not oil sands. Based on the talk page, this is what I could guess, and I'd like confirmation.

It seems that they were originally known by scientists, geographers as tar sands. The name oil sands only came about when technology advanced enough to make extraction easy enough for the public to pay attention, and eventually oil corporations started making investments in the projects. As a result, oil sands became the popular name.

Is this interpretation of the discussion correct? -- Zanimum 16:26, 7 March 2007 (UTC)[reply]

yes I do belive that it is, as you can get tar from oil and oil from tar but amongst the commonfolks the preferred term is oil sands, just like they say concrete not cement. -maxx- 66.99.49.226 18:23, 7 March 2007 (UTC)[reply]

I imagine the oil companies prefer the term "oil sands" because that doesn't bring to mind all the sludge in "tar sands", which then has to be disposed of. Thus, this euphemism makes it seem like a cleaner energy source than it really is. StuRat 18:34, 7 March 2007 (UTC)[reply]

Coefficient of friction between wheel bore and axle

How might someone determine the coefficient of friction between a wheel bore and axle given a setup like the one pictured here? Given that you know the mass and radius of the wheel, the radius of the wheel bore, the radius of the axle, the width of the wheel/axle contact, the mass of the weight on the string and the time for the weight to fall a given height, what equation(s) would give the coefficient of friction? dryguy 17:37, 7 March 2007 (UTC)[reply]

Do you really need to know the coefficient of friction, or do you just need to know which is best out of a series of wheels ? StuRat 18:31, 7 March 2007 (UTC)[reply]

I want to be able to compare different lubricants and be able to compare data with others using similar, but possibly not identical setups. The latter requirement gives rise to the desire to be able to compute the coefficient of friction in order to separate out differences in wheel mass, axle/bore diameter, height of drop, etc. dryguy 18:40, 7 March 2007 (UTC)[reply]

If the wheel is not slipping, then the only friction is between wheel-bore and axle. You could try to apply a force and measure the acceleration, but I imagine the coefficient-of-friction is so low (close to zero) that you will not be able to practically apply this technique. You might also try spinning the wheel at high rate of speed (perhaps use a power-drill with a known RPM rate), and determine the slow-down time of the wheel. Then you can determine the torque due to friction. I'll see if I can find simple equations to determine "mu-k" (kinetic friction coefficient) from the slow-down time. Nimur 20:22, 7 March 2007 (UTC)[reply]

I agree that wheel-bore/axle friction is the only friction. I just meant that the time for the weight to drop a given height will depend on other factors besides the friction, so it will be nice to have a way to ferret out the coefficient of friction in order to compare set-ups that have differences in wheel mass, height, etc.

The drill sounds like a good idea; the main difficulty will be selecting the right rpm to approximate what a car experiences on the track. Thanks for offering looking up the equations - it should be a big help. dryguy 21:13, 7 March 2007 (UTC)[reply]

indigestible edible muffins

Jim said that "they" used to manufacture and sell "edible muffins" that were indigestible. The muffins could be chewed and swallowed like regular food, but the chemical structure prevented the body from metabolizing the nutrients (or it contained no nutrients) resulting in complete elimination from the body with zero calorie absorption.

Is this true? What was this product called and how did it work chemically? Who was "they"? Why was it discontinued? NoClutter 17:49, 7 March 2007 (UTC)[reply]

I imagine it would be very rough on your digestive system. Everyone needs some fiber, but 100% non-nutritive fiber in that quantity would be overkill. StuRat 18:28, 7 March 2007 (UTC)[reply]

You could certainly bake something like that using artificial sweeteners in place of sugar and Olestra as a cooking oil. That would result in something with almost zero nutrients - yet which would be tasty and not do terrible things to your digestive system. SteveBaker 18:54, 7 March 2007 (UTC)[reply]

Tasty is a matter of perspective. Some people can distinguish between natural and artificial ingredients such as {sugar vs. saccharine or sucralose}, or {fat vs. olean}. Nimur 20:33, 7 March 2007 (UTC)[reply]

I certainly can, and Olestra causes "anal leakage", so I wouldn't call it free of side effects. If a delicious calorie-free muffin really could be created which had no adverse side effects, it would be a runaway success. If they canceled production, we can be reasonably sure it didn't meet all those requirements. StuRat 21:21, 7 March 2007 (UTC)[reply]

Full Moon Madness

I need help with the following issue. Please do not tell me I need psychological help or meds. I have noticed that everytime there is a full moon, I am anxious, short-tempered and have a general feeling of nervousness/anger. Does anyone experience this? Is there a scientific reason for this? Does anyone know of how I could curb these symptoms?

Are you female? If so, perhaps your monthly period simply happens to coincide with the full moon (give or take a few days)? SteveBaker 20:11, 7 March 2007 (UTC)[reply]

Are you a werewolf? If so, perhaps your monthly period simply happens to coincide with the full moon (give or take a few days)? Nimur 20:23, 7 March 2007 (UTC)[reply]

(You didn't sign your message - but looking at the edit history, I deduce that you are indeed female). I did some further research. Menstrual cycles typically happen on a 28 day cycle - but anywhere between 21 and 35 days is considered normal. The moon is full every 29.5 days - so it's very possible that your body might happen to be in sync with the full moon just by pure coincidence. It would be surprising if you were so perfectly in sync that this would be the case forever - but over a period of years, I bet you find that the relationship between the phase of the moon and these times of unease gradually drifts out of sync. Your symptoms seem quite believable - we married guys know only too well that we need to keep a low profile at "certain times of the month". Generalized grouchiness/anxiousness is certainly an absolutely typical symptom. You can certainly talk to your doctor (you might not want to start off by claiming to be a lunatic though! See Lunar effect) - I believe there are treatments relating to birth control pills that can tame the worst of the symptoms - but we aren't allowed to offer medical advice here - so "See your doctor" is as far as we can go. SteveBaker 20:29, 7 March 2007 (UTC)[reply]

Barring the possibility of some menstrual cycle coincidence, you should be aware that there is absolutely no scientific reason why a full moon should have an effect on anyone's mood. Your problem may just be your own superstition; I would recommend learning more of the real facts about the Moon— and try looking at it through binoculars sometime, and you'll see it's just a beautiful piece of geology.--Pharos 21:03, 7 March 2007 (UTC)[reply]

Also, maybe you spend a lot of time at the full moon thinking about the psychological effects of the full moon, which could make you nervous and jittery. --18.214.1.72 22:16, 7 March 2007 (UTC)[reply]

Not true i have heard of psychological studies that state that the full moon effects a person by drawing more blood to the head which can cause some of the symptoms that juliet mentioned. i will look for a source for this to back this up give me a bit Maverick423 22:19, 7 March 2007 (UTC)[reply]

No need to look it up - let's do the calculation. Let's say the gravitational pull of the full moon could result in blood being "pulled to the head". What is the gravitational pull of the non-full moon? It is the same. The amount of light reflecting from the moon to the earth should not affect the gravitational pull of the moon. --Bmk 22:27, 7 March 2007 (UTC)[reply]

heh it appears you are correct i revisited the place i found it on and it states that it does not effect the human body lol i guess i forgot to read that one word Maverick423 22:38, 7 March 2007 (UTC)[reply]

I also think women's periods can come to coincide with recurrent events. I forget where I heard this. But that would explain the regularity. 70.108.199.130 23:37, 7 March 2007 (UTC)[reply]

Well, it's a cycle, and it can be easily coordinated with other women. Depending on the intensity of the "problem," the questioner could be recommended to see a doctor to refer her/him to a psychiatrist. It could just be the menstrual cycle or a perceived effect coming from local superstition. [Mαc Δαvιs] X (How's my driving?) ❖ 01:08, 8 March 2007 (UTC)[reply]

If the two intervals coincide by chance - which is really likely if at typical human cycle is 28 days and the moon cycles over 29.5 days - there must be a huge percentage of women who's menstrual cycles just happen by pure coincidence to be 29.5 days. Since this feeling lasts several days, and the moon looks full for several days there is maybe a one in ten chance of it happening to coincide with the full moon. There must be literally millions of women who hit this point in their cycle on a full moon. It's not just likely - it's nearly certain that a large slice of the population hit the exact frequency and phase to match the moon. It means nothing - it's just a coincidence. SteveBaker 03:25, 8 March 2007 (UTC)[reply]

Stuttering and the neurotransmitter Dopamine

I believe there is a featured article Stuttering, and the article states, Dopamine Antagonists are used to treat stuttering.

My question is, what is the actual relationship with stuttering and the neurotransmitter dopamine?

Secondly, the featured article states, stuttering can be caused by anxiety.

Dopamine is the neurotransmitter involved with happiness. So anatagonizing dopamine will make the person depressed? --Parker007 20:21, 7 March 2007 (UTC)[reply]

Changing dopamine levels can have dramatic side-effects. Levodopa is a drug used to combat everything from schizophrenia to Parkinson's disease by elevating the dopamine levels. Yet, it sometimes has unwanted psychological side-effects worse than the original condition. I am not an expert, but I think there is not a direct one-to-one correlation between dopamine level and correct synapse function, let alone mental health. Nimur 20:27, 7 March 2007 (UTC)[reply]

i am trying to think

what give rise to thought?

what i mean is, if the brain works on the same physical and chemical laws that govern non living things, then thought generation should be an entirely random phenomenon. then how is it that as an individual i am able to think about what i want to think about?

59.180.16.107 20:53, 7 March 2007 (UTC)[reply]

Not knowing anything scientific, logically I would guess that the mind has set things to 'think' that will help keep you alive. This could be awareness of others, memory of past events, automatic responses. Self-awareness and [Consciousness]] are supposed to be two of humanities biggest 'divides us from the animals' characteristics. I suspect this ability to understand/realise ourselves and others gives us the ability to think beyond simplistic survival towards more advanced survival. I risk being 100% wrong here, but that's how I would think of it. How you choose what to think will be sparked by things you see, things you hear, smells, sounds, situations, taste any of the senses really. Great question though - hopefully someone with half a brain gives you an actual answer rather than just, well, drivel like me! ny156uk 22:01, 7 March 2007 (UTC)[reply]

Nope, you pretty much nailed it… I think, therefore I am. It's one of the olders questions to confound man, the oldest is "how can I get that girl's attention" ;). Vespine 02:26, 8 March 2007 (UTC)[reply]

But what about "we think, therefore we am?" Better instead say "thinking exists, therefore thinker(s) exist. Let me answer your original question with a question: if earlier conditions in an object must entirely determine the later conditions, plus perhaps some random noise, then how can "freedom of choice" exist? When you get right down to it, what is free will? What does it mean to have selective intent, to be able to make decisions? Or in other words, is freedom of choice just an illusion? If not, then it's outside of known physics, since modern physics only includes the pure determinism of Classical Mechanics and the statistical randomness of QM. Where does our apparent freedom to make decisions come into contemporary physics? Perhaps self-awareness isn't the mystery of consciousness, since a purely deterministic computer program could concievably observe its own operation yet remain deterministic. On the other hand, how could a computer program ever have the ability to observe the factors affecting a decision, then choose to ignore them and instead make the wrong decision intentionally, because it wanted to? --Wjbeaty 03:47, 8 March 2007 (UTC)[reply]

The questioner contends that physical and chemical laws yield an "entirely random phenomenon." I think this is fundamentally incorrect. If you drop an apple, there is no randomness about the direction it will fall. If you mix vinegar with baking soda there is no randomness as to what will happen. These are structured events governed by physical laws, which scientists can study and uncover. This is quite the opposite of your question. Perhaps you might ask whether our thoughts are entirely deterministic, or if there is enough complexity in the system to yield complicated behavior. Or perhaps you subscribe to the notion that quantum mechanics and its sub-atomic uncertainty propagates up to macroscopic events like chemical reactions (this is a disputable issue, depending on how you interpret the statistics and how you choose to define random). Nimur 17:53, 8 March 2007 (UTC)[reply]

Aerodynamics

Why are some things that need to be aerodynamic not pointy in the front? Wouldn't hand gun bullets travel farther and faster if they were sharp instead of round at the front? Wouldn't airline jets have less drag and be more efficient if they had pointy noses like fighter jets instead of those round bubbly nose cones?
For the first example someone told me they're meant to be that way so they don't pierce right through the victim and hit someone else. Which is just silly because you can still make them aerodynamic and use less gun powder. What about the airplanes example? Is there any harm in making the nose too aerodynamic? —The preceding unsigned comment was added by 209.53.181.32 (talk) 22:24, 7 March 2007 (UTC).[reply]

Believe it or not, there is at least one article dedicated to that exact question - you can read all about it at nose cone design, and also some in nose cone. It appears that simply making the nose slimmer is not sufficient - there are more complicated aerodynamic considerations to take into account. And also, don't forget that the sharper the nose cone, the longer it must be to connect to a body of given width, so there is much more metal-air frictional interface. But I know very little about aerodynamics. --User:bmk

I've corrected bmk's links. To summarize, however, a pointy nose is not necessarily aerodynamically ideal. The first article specifically notes that for velocities below Mach 0.8 (such as airliners), blunted nose cones are ideal. — Lomn 22:36, 7 March 2007 (UTC) (after edit conflict)[reply]

Also note that bullets from rifles have a spin, so air isn't just moving straight along them. Thus, if you were to add a nose cone, it would need to be more of a corkscrew shape. Also, I believe any point on a bullet would cause the bullet to tumble once the point got slightly off center, and a tumbling bullet is much less aerodynamic. This is a basic stability issue. While passenger planes are designed to be stable, which makes them easy to fly, fighter planes are designed to be aerodynamically unstable, which allows for quicker turns and maneuvers, and a round nose is more aerodynamically stable than a pointy one. StuRat 23:19, 7 March 2007 (UTC)[reply]

I've coma across this same question in model rocket circles, those guys know a lot about nose cones. This site has some great info and here is even a piece of software to design nose cones. Vespine 02:23, 8 March 2007 (UTC)[reply]

One critical concept involving pointy-fronts on non-supersonic aircraft: if the nose is pointy, and if it hits the air at an angle, then there will be flow-separation on one side and sideways-directed frictional forces which lead to tumbling. Or if a wing has a sharp leading edge, and it hits the air with a positive attack-angle, then there will be major flow-separation above the wing, and major turbulent friction. It's called a "stall." Sharp leading edges cause the air-flow to peel loose from the object's sides. To avoid this situation, eliminate the sharp front parts and make them smoothly rounded. Pointy parts are only good for supersonic objects, and for objects having guide-fins which prevent it from tilting with respect to oncoming air. --Wjbeaty 03:30, 8 March 2007 (UTC)[reply]

Bullet noses are only pointed in the case that you want it to go really really far. See .223 for an example of a rifle bullet designed for distance, and 9mm Luger for a handgun bullet designed for stopping power. The idea that you can simply use less powder in a handgun bullet is erroneous, the purpose of the bullet is to hit one target and do as much damage as possible, to do this you need lots of acceleration AND lots of mass. --66.195.232.121 15:01, 8 March 2007 (UTC)[reply]

Waking up from a bad dream

This may seem kind of bizzare--I don't know if anyone else experiencces this. When I have a bad dream, usually I realize it's a dream near the end (just before something realy bad happens to me or someone else, like getting attacked by the beast or what not). The wierd thing is, I'm still terrified and I feel literally stuck in the dream. At this point, I must be consious because I'm trying to "get out" of the dream. Then I try to wake myself up by "jerking" by neck or torso... and the strangest thing is that it always works by the second or third try. A couple of questions: Why on earth don't I ever think "Who cares, it's just a dream, so why don't I try to enjoy it like a horror movie". The second question is, why do I need to physcially shake my body to wake up, why can't I just open my eyes and wake up?
This is not just one incident, it's happened to me so many times. Does this all sound bizzare or does anyone here know what I'm talking about? —The preceding unsigned comment was added by 209.53.181.32 (talk) 22:40, 7 March 2007 (UTC).[reply]

What you are describing is so common that it has a name: a hypnic jerk. Take a look at our article on hypnagogia, which basically applies (though strictly speaking, because you're waking up rather than falling asleep, you're in a hypnopompic rather than a hypnagogic state). - Nunh-huh 23:06, 7 March 2007 (UTC)[reply]

(1) If you thought this, that is the best possible thing you can do in a dream. See lucid dreaming. It is really cool :) (2) Normally I just take my fingers and pull my eyelids off of contact with my eyes a few times, kind of "popping" them, or just "opening" them past where they would normally physically be able to fold up. If you are lucid, I would recommend trying your best to stay in the dream. The most effective technique for this, is mysteriously, spinning around on your vertical axis. I'm really not sure hypnic jerk has anything at all to do with this, since it is a physical muscle spasm that happens when you are falling into sleep, could that be clarified if I'm missing something? I recommend you do your best to become lucid, and know, accept, and understand that you are in a dream and you can do anything you want. :) What would you like to be able to do in normal life but is often constrained by social or physical limitation? Favorites are flying and sex. You may be on your way to becoming a lucid dreamer! Good luck, hope I helped any. [Mαc Δαvιs] X (How's my driving?) ❖ 01:03, 8 March 2007 (UTC)[reply]

If I have a lucid dream I usually have to fight to stay asleep :( Vitriol 01:37, 8 March 2007 (UTC)[reply]

Long ago I've had similar eperiences with nightmares, but in order to escape, I used my voice to break out of the dream. If I could use my real-world vocal chords to say "raaaahhh," then I broke out and awakened. (I think I was awakened by the sound.) But after years of nightmares, today I can usually just watch the events without fear. As for being able to enjoy nightmares, I don't think most awake-state skills are available when sleeping. "States of consciousness" are weird things in that all of the skills developed during one state aren't available during another state. Classic example: if you study for an exam while drunk or while very sleepy, then the learned material won't all be available if well rested or sober during the exam! So, recall how scary a horror movie was during your early childhood. Toleration of horror movies is usually a learned skill. Since we learned that skill when awake, it's not necessarily available during sleep. So... we react to nightmares as if we were little kids confronting a horror movie. Learning to enjoy nightmares takes time, and unfortunately it's a *separate* process from learning to enjoy horror movies. For more info search on "state-dependant memory" google search--Wjbeaty 03:18, 8 March 2007 (UTC)[reply]

As for "Why on earth don't I ever think "Who cares, it's just a dream, so why don't I try to enjoy it like a horror movie", it's probably a good thing that you don't think that. I've always believed that dreams are not "just dreams". They are messages from the unconscious to the sub-conscious. They mean something. What they mean, or whether any particular dream is significant or not, is not my or anyone else's place to say. Only you can work that out, if it's important enough for you to know. JackofOz 03:53, 8 March 2007 (UTC)[reply]

I am a skeptic and I am not sure there is much scientific evidence, if any evidence at all. "Evidence is not the plural of anecdote." In my opinion, it seems logically fallacious since I can completely control any of my dreams. So my unconscious and sub-conscious is taking a break while my conscious takes over driving for a while? It's a personal belief thing. Since we're on the subject, I'd like to ask what compelling evidence there is for an unconscious and sub-conscious? We usually assume a conscious. [Mαc Δαvιs] X (How's my driving?) ❖ 07:55, 8 March 2007 (UTC)[reply]

Well, if you remember that your 'conscious' and 'subconscious' are both just you, there isn't really a problem. Have you never sort-of known something that you haven't properly thought about consciously? As in, something bothers you about a situation, then you have a proper think why, and you realise through conscious thought? Subconscious is just a name for the process that is doing that first thinking, but that doesn't mean there are two seperate people in your head. It's all you. It's just useful semantics. Dreams seem to me to be a way of sorting out the thoughts in your head. Since you don't tend to think about everything consciously all the time, while it might be 'at the back of your mind', they can bring up things you didn't realise you were thinking about. You could call this 'messages from your subconscious to your conscious', because that is a convenient way of putting it. An example (although anecdotes are not reliable evidence, it serves to explain what I mean): Every so often, when I'm living away from my family, I get a dream where some natural disaster sweeps in and I'm trying to get them all safely out. I wake up, thinking about the dream, and realise that I'm missing my family and worrying about them, having not seen them for a while. I visit home. It's only my own thoughts, no outside intervention, but it is a useful way of picking up the thoughts and feelings that I don't have time to think about, or don't want to think about, when I'm awake.

On to lucid dreams. In lucid dreams you are aware of dreaming and appear to have conscious control over the dream, yes? However, studies (damn, where are they?) have shown that when questioned shortly after waking, lucid dreamers report not retaining constant lucidity throughout the whole dream. So they have moments when they act as if it is real, or they do/think something that makes no lucid sense. So your actual lucidity may not be as total as you'd think. Another way of looking at it is that you have exchanged one valuable function of sleep for the excitement of lucid dreaming. However, I imagine you end up doing most of the thought-sorting you'd normally do in a dream, just with the impression of more control. If not, I would expect your memory to be shot to pieces :-P

Finally, everyone is in complete control of all their dreams, because dreams are all in the head. Just because it is what we are calling the 'subconscious' doesn't make it any less you, in your brain. Although scans have shown that dreamers usually have sections of their brains less active in such a way as to render them functionally mentally handicapped in the dream. Which explains some of the odd reasoning. (And if you want proof of unconsciousness, let me find you a general anaesthetic.....) (Possibly all this is ranting and should be removed?)

As to the jerking, I get that too sometimes. It seems to be related to the hypnogogic jerk, in me at least. It's like my muscles get hooked back up to my 'dream muscles', so a dream motion causes an actual motion, and that movement is enough to jerk me awake. I used to find realising I was asleep woke me straight up, unless I tricked myself into not fully realising (by pretending it was a film or book I was watching/reading/writing), but in recent years I've had to claw my way awake if I don't like it. I think it's just one of those things. You're not alone :-) Skittle 01:49, 9 March 2007 (UTC)[reply]

I guess I'm lucky because all of my dreams are "lucid" dreams (I know I'm dreaming) and I'm fully able to just open my eyes at any time and wake up.. as long as I'm dreaming. --⁪froth^T 09:11, 8 March 2007 (UTC)[reply]

The "dream producer" can in my experience work amazingly fast. If the phone starts ringing, your mind may try to keep your sleep going by incorporating its sound into the dream, by creating an instantaneous "backstory" which leads up to you hearing the ringing as part of the dream action, like you pressing a doorbell in the dream. Similarly if the clock radio is giving the news, the words of the announcer may be incorporated into the dream. The point of this in the extreme is that your body may be about to give a big movement and the dream creator provides an instant nightmare to "explain" it. We do not provide medical advice, but if this causes problems for you or a bed partner, you might wish to discuss it with your doctor. You might be interested in Sleep , Dream , Sleep paralysis , Lucid Dreaming , Sleep disorder , Night terror , Restless legs syndrome , Sleep paralysis , False awakening , and Polysomnography . Edison 22:54, 8 March 2007 (UTC)[reply]

So that time when I had a dream where people decided to start ringing a bell just before my alarmclock started ringing, I made all of that up after I heard the alarm? A bit worrying if I did, messing up my own memory deliberately, and it didn't even work as I still woke up :( HS7 20:15, 9 March 2007 (UTC)[reply]

Actually I just realised, it didn't do it deliberately as I was asleep and therefore couldn't deliberate it, so I must have just done it on purpose :] HS7 20:16, 9 March 2007 (UTC)[reply]

Homework (but it's only a small part of a question in a series)

So. AP Physics C. We're working on circuits and we've got this big packet of questions. There are diagrams I can't reproduce, but the question I'm asking is basically theoretical. I've got an idea, and I just want to make sure it's right. So the circuit in question is roughly symmetrical. A wire runs off the positive end, forks into a resistor and a bulb of unknown size, then rejoins and forks again, this time into two bulbs (of unknown size) and two resistors of a different resistivity (if that's the right word) from the first one. The four wires then go back into another fork into a bulb and a resistor, the same as the first two. In other words, to simplify it, the positive and negative charges follow the same path until they meet at those four middle obstacles (2 equal resistors and two questionably equal bulbs). The question is whether, for those two questionably equal-in-size-and-thus-resistivity bulbs, the CURRENT FLOW in one is equal to that in the other regardless of any size difference. My feeling is that since the same net flow flows regardless, the same current will flow over each bulb, just slower (this is clearly the wrong term, but I think the gist comes across) depending on bulb size. In other words, the ratio of flow between the two would be a simple 1:1 regardless of size, and the ratio of that current flow to the flow of current through the battery would be 1:4 because the charge is equally distributed through the four "obstacles" in that equal level of charge, so to speak. Correct? Hopelessly wrong? Thanks for any feedback, 70.108.199.130 22:36, 7 March 2007 (UTC)[reply]

I learned about resistors and stuff like this when i was in highschool however i cannot give you a conclusion unless i see a diagram as that is how i solved all problems like this. as far as the flow you got to realise that you placed resistors in the circit which in turn would reduce the voltage of the power going through your wires. and with out exact resistence stated we cant know how much of that power is taken by the resistors. try to make a diagram or something so i can check it out unless someone else can solve this before you do.Maverick423 22:45, 7 March 2007 (UTC)[reply]

also realise that the size of the bulbs dont effect the flow of power unless they too have some sort of resistave material inside them to do so. Maverick423 22:48, 7 March 2007 (UTC)[reply]

acctually i think i may have something for you to think of for what you are trying to do. this is my rough diagram ( 120 v source)====B===B===B===B (back to 120 v source) the wires here are connecting in a perallel fashion which means 120v are distributed equally however if they were connected something like this (let me try) (120)==<B}==<B}==<B}==<B}==(120) the power is spread out into the bulbs so 120v becomes 30v per bulb because the power is spread within the bulbs. really this is alot simpler to explain in a diagram but im trying my best to help you with what i got Maverick423 22:57, 7 March 2007 (UTC)[reply]

Here's my attempt at a diagram. None of the bulbs are necessarily equal, though I think the top and bottom ones have to be. And the large/small bulb convention is based on bulbs he's had us use in experiments, which do have different resistivities.

   ________________ _______
   |               |       |
   |               |       |
--------         bulb     1.6V resistor 
4V battery         |       |
  ---              |       |
   |        -----------------------      
   |        |      |       |      |
   |      .8V R   bulb    bulb   .8V R
   |        |      |       |      |
   |        -----------------------
   |               |       |
   |             bulb     1.6V R
   |               |       |
   -------------------------

70.108.199.130 22:58, 7 March 2007 (UTC)[reply]

the energy is reduced each time the power passed a bulb or resistor unless the (hot) wire is perrallel to the neutral one. but since your trying to reduce the volts this would be pretty much wasteful. however the volts if connected from the resistor to the bulb will be reduced and you can still maintain 4.5 v by bypassing the resistor with a parallel wire. ill see if i can make you a diagram

Yeah. I get that. The question is whether the flow of charge through those two middle bulbs is equal regardless of any difference the two might have in resistivity. 70.108.199.130 23:07, 7 March 2007 (UTC) Oh, and it isn't 4.5. I copied that down wrong and that may have thrown you, cause then the numbers wouldn't have worked.[reply]

sorry for the late response i had a emergancy. well according to what you provided it seems that the bulbs assuming they use about 1v each will not be equal. but seeing as how there are 2 diffrent sizes i would assume that the smaller of them is .4v and the bigger about .8v which would mean that both the center bulbs should have more then enough energy to be powered but they wont be equal seeing as how the small bulbs will only use .4v and the resistor next to the small bulb blocks off 1.6v. this is of course assuming that this is the voltage usage of the bulbs either way the bulb next to the resistor will have to use 1.6v to allow both bulbs in the middle to be equal to each other. the .8v resistors will not seem to have a effect since they are not in the direct current of the power source they are well out of the way. Maverick423 02:21, 8 March 2007 (UTC)[reply]

What's a bulb? If you mean a traditional Incandescent light bulb, then we need to decide if you have a theoretical bulb or a real bulb. A theoretical bulb has a fixed resistance and no inductance. For this, you can create an equation that describes this circuit exactly as a pure series/parallel resistive circuit: simply assign resistances (B1, B2, B3, and B4) to each bulb and plug them in. Real bulbs are very different, however, for two reasons. First, A real light bulb filament is a coil,and a coil is an inductor. This is means that current cannot change instantaneously. Second, a real bulb has a change in resistance with temperature, and therefore a change of temperature with time*current. This means that when you flip the switch (i.e., when the voltage changes instantaneously from 0 to 4v) you initiate a complicated time-varying set of changes in the current through each bulb. If we characterize each bulb as having a fixed inductance L, a fixed coefficient of resistance/temperature C, and a fixed dissipation of power P, then each bulb is (L,C,P). With four bulbs, you have twelve numbers and a whole lot of calculus. I would speculate that for some valid sets of bulbs, your circuit will exhibit chaotic behavior. -Arch dude 02:38, 8 March 2007 (UTC)[reply]

The homework question is somewhat of a "trick question" because it tests you for the "sequential" misconception, the "current sharing" misconception, the "absolute voltages" misconception, etc. Many beginners incorrectly believe that batteries supply a (constant) current which then divides itself as it hits branch points. To avoid all these mistakes, base your reasoning entirely upon Ohm's law: the current through a particular resistance is only determined by the voltage measured between the two resistor terminals, divided by the resistor's ohm value. Ask yourself this: will you ever measure two different voltage values across the terminals of two separate lightbulbs if the two bulbs' wires are connected to each other? Also ask: do you *know* that the ohms value of those two bulbs is equal? --Wjbeaty 02:48, 8 March 2007 (UTC)[reply]

Voltage will be the same across parallel elements. BTW, what are those resistors with voltage? Resistors don't directly regulate voltage. Let me read this question over before I answer in more detail. --Wirbelwindヴィルヴェルヴィント (talk) 03:00, 8 March 2007 (UTC)[reply]

Ok, you're thinking if the two bulbs parallel to the (magically) 0.8 V resistors have the same resistance, and we're assuming light bulbs to be a resistor and not an RL circuit, then yes, you're correct in thinking that the current through each of those two bulbs will be the same. However, they do not move slower, just that you have less current (amperage). For the other part, current going through each of those middle bulbs are the same through each of the four branches... That part is the wrong assumption, unless the resistors and the bulbs have the exact same value. Then yes, the current through each bulb will be 1/4 of the total. But if it's not: If the 0.8 V resistors have less resistance than the bulbs, then less current will blow through the bulbs than the 2 resistors, and vice versa. I'll draw a diagram right now to show you more clearly. --Wirbelwindヴィルヴェルヴィント (talk) 03:11, 8 March 2007 (UTC)[reply]

Ok, I uploaded an image to help demonstrate. Assuming those are not 1.6V resistors and 0.8V resistors, but that there is a voltage drop across them of those values, that means everything parallel to them has the same voltage. That means both Bulb A, Resistor A, Resistor D and Bulb D have the same 1.6V drop. This also means that Bulbs B, C, and Resistors B, and C have the same 0.8V drop. So the question (I think) is, do Bulbs B and C always have the same current. The answer is no, because the current through those is dependent on the resistance of Bulb B and Bulb C, which is given by dividing the voltage by the resistance, or 0.8V divided by the resistance of Bulb B and 0.8V diided by the resistance in Bulb C. So from that, you can see that they will have different current if the resistances vary.

As for the total current through Bulb B + Bulb C + Resistor B + Resistor C, it is the same as the current through Bulb A + Resistor A, which is the same as the current through Bulb D + Resistor D. The actual value is computed by finding the equivalent resistance of all 8 elements, and then dividing 4V by that total resistance. But that only gives you the current through each set of parallel elements. Hope this helps. If not, ask here or you can reach me on my talk page. --Wirbelwindヴィルヴェルヴィント (talk) 03:50, 8 March 2007 (UTC)[reply]

. When exact circuits are specified, exact answers can be given. Circuit equivalents can be determined and circuits can often be simplified and solved, using such tools as Ohm's Law, and rules for parallel resistances, series resistances, current divider. "The question is whether, for those two questionably equal-in-size-and-thus-resistivity bulbs, the CURRENT FLOW in one is equal to that in the other regardless of any size difference. My feeling is that since the same net flow flows regardless, the same current will flow over each bulb, just slower" I know of no electrical principle that" the same net flow flows regardless." When you say "the same current will flow over each bulb, just slower" that implies a misunderstanding of what electrical current is compared to what electrical charge is. One might say "the same charge will flow through a circuit element, just slower" which would be less current, but it is quite incorrect to say the same current could flow but more slowly. Re-read in your textbook the difference between charge (coulombs) and current (amperes, or coulombs per second) and abandon attempts to analyze circuits based on motivation of charges to do this or that. Look at an example in your text of circuit reduction, or provide exact circuits to be analyzed. In my sad experience, attempts to analyze complex circuits qualitatively and verbally fail utterly. I agree with Wjbeatty and Wirbelwind. The key question appears to be if the two unknown bulbs identified by Wirbelwind as Bulb B and Bulb C which are connected in parallel will carry the same current. As the question is interpreted, they each have the same voltage applied across them from the nodes shown above and below. As stated, they do not necessarily have the same wattage and thus can have different resistances. What if Bulb B was a 10 watt bulb and Bulb C was a 1 watt bulb? Then Bulb C would have far less current flowing through it. Circuit elements in parallel need not have the same current flowing through them at all, and often have vastly different currents. All the rest of the circuit has no relevance to this question. Edison 16:17, 8 March 2007 (UTC)[reply]

Energy / momentum / mass

The relativistic energy-momentum equation is E² = (mp)² + (mc²)². For a stationary object (p=0), this can be reduced to E = mc². Which of these relations / equations was discovered / derived first? →Ollie (talk • contribs) 23:18, 7 March 2007 (UTC)[reply]

Aren't they essentially the same equation? E=mc² is the famous one but it may be because it rolls of the tongue so much nicer ;) Einstein may have gone through the 1st one to arrive at the simpler one but there is no way someone else came up with the 1st for Einstein to just reduce it into his famous equation. Once you have one the other seems arbitrary, chicken or the egg? Vespine 01:06, 8 March 2007 (UTC)[reply]

Einstein derived the first equation from the mathematics of Lorentz transformations when he was creating the Special Theory of Relativity. After that, he did what any mathematical physicist would do and set p=0.MisterCDE 06:13, 8 March 2007 (UTC)[reply]

March 8

Magnetic field formula derivation

I am curious as to how the equation shown here is derived, specifically, the inverse cube relationship, and with a minimum of calculus, if that's possible. If anyone could point me to a proof/explanation on the Internet or give me some tips as to how to go about deriving it, it would be much appreciated. -Elmer Clark 03:07, 8 March 2007 (UTC)[reply]

If you're just interested in where the inverse cube part comes from, it's pretty straightforward. First of all, for a the electric field of a charged particle, or a light source, or a gravitational field, the intensity of the field falls off as the inverse of the square of distance. Conceptually, you might think of a hollow sphere as a model—the field originates with the object at the centre, and the intensity of the field gets 'spread out' over the surface area of the sphere at any given radius. Since surface area increases with the square of radius, the field strength falls of by an inverse square relationship.

Now think about a magnetic field. Magnetic dipoles are just that – dipoles – there's so far never been discovered a magnetic monopole (though there are physicists who hunt for them). Think of each pole of a magnet as having its own field, where each field is equal in strength but the two are opposite in magnitude. Any point around the magnet influenced by one field will see that influence weakened by the effect of the other field.

Treat the net magnetic field, then, as the sum of two fields following an inverse square relation. The first field will be at a distance x, the second at a distance of x + a, where a is some small number relative to x. The total field will then be proportional to 1/x² - 1/(x+a)². Add those up (expand the brackets and bring everything over a common denominator) and...and you'll have a mess of terms. What you do then is make the 'far field' approximation; that is, assume that the distance x is much larger than a, so you need only keep the terms of the highest order in x as terms with fewer xs and more as will tend to be negligibly small. Presto! The inverse cube relationship comes out.

The rest of the terms in the dipole formula come from various physical constants, or from dealing with the effect of 'viewing' the magnet from an orientation other than directly end-on. TenOfAllTrades(talk) 03:41, 8 March 2007 (UTC)[reply]

If you look at the electric dipole, the gradient of the potential also kicks out an r^3 term, along with the 4 pi. you might pick up a book on electromagnetics for engineers, cause they are easier to read.172.161.102.213 12:30, 8 March 2007 (UTC)[reply]

I took emag centuries ago, and I wish I had bought Div, Grad, Curl, and All That or some other book to supplement that main text. I never understood it very well, but I know EE/physics gets a ton easier if you force yourself to learn the mathematics part.172.161.102.213 12:39, 8 March 2007 (UTC)[reply]

Thanks fellas. -Elmer Clark 23:27, 8 March 2007 (UTC)[reply]

Ptolematic system

Did retrograde motion inspire the idea of epicycles in the Ptolematic system? Thanks very much for responding. 208.72.125.187 03:32, 8 March 2007 (UTC)[reply]

I don't believe that apparent retrograde motion was observed until Tycho Brahe, or at least we have no record of it being observed prior to him. However, I believe the ancient Greeks did notice that the paths the planets traced in the sky were not followed at a constant speed. That is, if an object takes X days to complete an apparent orbit around earth, it's not necessarily 1/4th of the way around the Earth in X/4 days. This discrepancy needed some explanation. The real explanations are that those planets don't orbit the Earth (so the Earth isn't in the center of their orbits), and they follow elliptical orbits, not circular, with the object they orbit at one of the two focus points, not the center. StuRat 08:05, 8 March 2007 (UTC)[reply]

Really? That seems to contradict Deferent and epicycle. And if retrograde motion hadn't been observed before, then what was the point of epicycles? --Allen 08:09, 8 March 2007 (UTC) [I left this comment after StuRat had written only the first sentence of his response above. --Allen 08:23, 8 March 2007 (UTC)][reply]

Okay; that explains why we would have had epicycles before. But what you're saying still contradicts our two articles you and I linked to. Why do you say we have no evidence that retrograde motion had been observed before? If you're right, and a source can be found, we ought to change the articles. --Allen 08:23, 8 March 2007 (UTC)[reply]

That article states that retrograde motion was used to develop the epicycles system. In that case, Tycho Brahe must have rediscovered retrograde motion and/or documented it to a new level of accuracy. StuRat 08:19, 8 March 2007 (UTC)[reply]

Thanks. I don't know why I didn't get an edit conflict warning when I posted my last question. --Allen 08:25, 8 March 2007 (UTC)[reply]

More precisely, it is quite easy to observe retrograde motion because the two inner planets, Mercury and Venus, never have a greater distance from the sun than 60 degrees. So, they move one direction, and after that (some months later), back. --Rwst 15:21, 8 March 2007 (UTC)[reply]

I wasn't really counting that as retrograde motion, although I suppose technically it is. I was thinking of the more subtle retrograde motion of Mars, etc. StuRat 17:03, 8 March 2007 (UTC)[reply]

Retrograde motion was long understood (it is easily observable in Mars) and was exactly the stimulus for epicycles, yes. Epicycles existed before the Ptolemaic system, though. And they were not discovered by Brahe, who came long after Ptolemy. --140.247.252.156 17:41, 8 March 2007 (UTC)[reply]

I believe that retrograde motion of planets has been known for a very long time - in fact, the word "planet" means "wanderer" because the ancients noticed that some of those little bright dots wandered about (forward AND backwards) where the majority of the stars only travel in one direction. SteveBaker 22:54, 8 March 2007 (UTC)[reply]

Surely "wandered" is because they wandered with respect to the stars, not specifically because they changed direction. --Anon, March 9, 00:44 (UTC).

Energy Supplements

Ive been doing a lot of weight training lately and running and I was wondering if there was anything good out there to give me energy. I'm taking my vitamins and everything, but I'm still always tired. I sleep for about 8 hours. Has anyone used hydroxycut or something else that worked well for them? —The preceding unsigned comment was added by 76.167.159.75 (talk) 04:04, 8 March 2007 (UTC).[reply]

Go see a doctor. Ocarina Cave Girl 04:58, 8 March 2007 (UTC)[reply]

I don't think many people are going to spend money on an appointment to ask about wanting to feel like you have more energy. I am rather skeptical of any energy-producing or fat-burning pills on television commercials, personally. Vitamins are good for you, don't let anybody tell you they aren't, but you can drop the fish oil and chondroitin sulfate if you have it. I'm sure somebody else can help you more than me. [Mαc Δαvιs] X (How's my driving?) ❖ 07:49, 8 March 2007 (UTC)[reply]

It might be a glycemic index problem. Sugars are turned quickly into energy, protein and starches are turned into energy over a moderate period, and fats are turned into energy over a long period. So, ideally each meal should be a combo of those sources of energy. Eating primarily sugar would guarantee a sugar crash when that energy quickly runs out, while eating only fats would leave you low on energy for hours until that energy started to kick in. Also, while not exactly healthy for you, caffeine can help to keep you awake. Just avoid consuming it in the afternoon or evening, or it may interfere with your sleep. StuRat 08:02, 8 March 2007 (UTC)[reply]

Sometimes the simple answer is the one we miss quickly. Eat more. This might sound like too quick an answer but you will find it works out very well. Try to eat alot of complex carbohydrates like those found in whole wheat bread and breakfast cereal. It's often a smart idea to have a small meal before a workout. A piece of fruit,some slices of bread and about a glas worth of skimmed/low fat milk can work wonders. Don't overdo it though, a heavy workout on a full stomach is asking for a sore stomach.

I would like to stress that a lot of people tend to forget to increase their nutrient intake when they start an exercise routine. Depending on how often you go to the gym or jog this could mean that you might have to almost double your caloric intake in the span of about a month. Though most of us won't need to increase our daily intake by that amount it might be a good idea to compare what you are taking in to what you are burning off. There are quite a few tables online which list the caloric value of many food stuffs. (which I can't be bothered to look up for you right now because I'm lazy)

Don't forget that it's not all about calories. It all depends where you get it from, most of it will come from complex carbs. You'll need plenty of protein to keep those muscles in tip top shape and a bit of (mainly unsaturated) fat because well we just need fat for alot of body processes. Besides, a diet completely devoid of fat is most likely hell on the tastebuds. You might also want to check out this website http://www.exrx.net .Good luck PvT 09:32, 8 March 2007 (UTC)[reply]

I find that occasional small snacks between meals help, especially if they have a lot of sugar :) Or you could just do slightly less each day :] HS7 19:16, 8 March 2007 (UTC)[reply]

Eating foods with a lot of sugar is not a great idea if you want to keep your energy levels up. You will end up burning out rather quickly. As Hidden Secret 7 suggested, complex carbs are a good source of energy. − Twas Now ( talk • contribs • e-mail ) 20:23, 9 March 2007 (UTC)[reply]

Actually I'm sure I meant simple carbs :) HS7 10:31, 11 March 2007 (UTC)[reply]

Inductive Heating

We know that resistive components dissipate heat. Any idea why do we say that domestic electrical water heaters and iron boxes are inductive? Is it because of their design?Can it be eliminated?210.212.194.209

I would assume that it's because to save space, the resistance is looped back and forth so you don't get a super long piece of metal, but a coil like an electric stove etc. However, when you do that, it has induction. --Wirbelwindヴィルヴェルヴィント (talk) 05:41, 8 March 2007 (UTC)[reply]

See also the Inductive heating article. DMacks 16:31, 8 March 2007 (UTC)[reply]

Well its got nothing to do with RF heating,just plain old heating coils running from the power supply. —The preceding unsigned comment was added by 59.92.240.161 (talk) 12:02, 10 March 2007 (UTC).[reply]

Plasma TVs always have to be right side up or broken.

At Best Buy, they told me that Plasma TVs had to always be up and if it tilts too far to the right, lays down, etc. (you know when moving it and it's off) that it is broken for good because the plasma gets out of alignment and your entire TV gets permanent burn marks the next time you turn it on. I was told that for some models where if you wait 48 hours, the plasma will straighten out by then. Well I found nothing on google or Wikipedia about Plasma TVs always having to be upright or it breaks them. Anyone know anything about this or even heard of it? SakotGrimshine 06:01, 8 March 2007 (UTC)[reply]

Best Buy employees really seem to enjoy BSing, or generally making stuff up when they don't know something. According to the vast interwebs, the reason for transporting plasma TVs vertically is that the fragile screen is easy to break when they're horizontal (due to the weight of the glass pressing against it). [5] [6], etc. It's definitely something to keep in mind, but not for the reasons you were told. The plasma in a plasma TV consists of ionized (when the TV is on) xenon/neon gas. Turning the TV isn't going to have an effect on it. -- Consumed Crustacean (talk) 06:24, 8 March 2007 (UTC)[reply]

When we were setting up our 46-inch plasma part of the set up involved laying it face down on the glass. [Mαc Δαvιs] X (How's my driving?) ❖ 07:44, 8 March 2007 (UTC)[reply]

And I just read a shirt that said you know you're an engineer when... people at Best Buy can't answer any of your questions. --Wirbelwindヴィルヴェルヴィント (talk) 16:29, 8 March 2007 (UTC)[reply]

Missed periods

How many missed periods are usually taken as "nothing to be worried about" in an adult female? What are the causes and effects? I don't see a part in any of our articles on this! Am I missing it? [Mαc Δαvιs] X (How's my driving?) ❖ 07:41, 8 March 2007 (UTC)[reply]

I believe it varies by woman; some have very regular periods, while others have highly irregular periods. Also, athletic women can have their periods stop due to insufficient body fat, and some birth control pills are designed to interfere with the normal cycle. StuRat 07:52, 8 March 2007 (UTC)[reply]

do keep in mind that some women go into denial when they miss periods so that is why they start saying "its nothing to worry about" if anything i suggest a test =) also like sturat says maybe shes just to skinny. however most birth controls are ment to stableize the menstral cycle. the pills at the start stop her period while the pills at the bottom allow her to ovulate. but then again it depends on what kind you get (or since i assume your a guy what kind your girl gets)Maverick423 14:37, 8 March 2007 (UTC)[reply]

The pills at the bottom are actually placebos, meaning they don't do anything. If you skip those pills, and just start the next pack, voila! No period! --Candy-Panda 10:55, 9 March 2007 (UTC)[reply]

In this era of accurate home testing for pregnancy women don't just wait for their "friend" to arrive to confirm non-pregnancy after they have cause to think they might have become pregnant. Edison 15:47, 8 March 2007 (UTC)[reply]

yes true the test are very fast and can give peace of mind however they arnt always accurate. in a well personal issue we went through 4 test just to confirm that she wasnt pregnant. the first one didnt show any lines but see through imprints of them so we didnt know the result of that one. the second showed that she was. the third and forth showed she wasnt. over all outcome of all this. no kid =)Maverick423 15:56, 8 March 2007 (UTC)[reply]

I'm so..congr.... I give up. I never know which one people would rather have =P Is she just rather slender or taking birth control then? Don't worry if it's too personal or whatnot, but I'm curious about it for my future. --Wirbelwindヴィルヴェルヴィント (talk) 16:27, 8 March 2007 (UTC)[reply]

At the other end of the age range, it's apparently pretty difficult for a perimenopausal woman (or her doctor) to assess her fertility and her periods can become sporadic. Because ordinary birth control pills simulate normal hormonal cycles, they can mask some aspects of menopause and make it difficult to assess the true state of affairs.

Atlant 16:56, 8 March 2007 (UTC)[reply]

Weight Training and Fat Loss

I'm trying to lose weight and my trainer has me do a lot of cardio and weight training. Does the weight training reduce the amount of muscle loss while I am losing weight? —The preceding unsigned comment was added by 76.167.136.84 (talk) 08:02, 8 March 2007 (UTC).[reply]

Weight training increases your muscle mass. Muscle weights more then fat (it also burns fat for energy, basically). So if you're adding muscle and decreasing your body fat you may gain weight. You will want to keep a log of your body fat percentage if you're trying to lose weight (and by weight I assume you mean fat and not raw weight).--droptone 08:38, 8 March 2007 (UTC)[reply]

I can give you a quick answer on that question. Yes he's trying to reduce muscle loss due to all the cardio you are doing. The body becomes catabolic when it's glycogen stores are depleted and will start to break down and burn off the protein in your muscles. This is a bad thing, since you need those muscles to burn of fat. Largers muscles require more energy when active but also when in rest (see basal metabolic rate). Depending on how fast you wish to lose body fat you might be able to actually gain muscle mass, but this requires you to lose body fat very slowly. PvT 09:10, 8 March 2007 (UTC)[reply]

I like Richard Muller's articles on the subject.[7][8]. [Mαc Δαvιs] X (How's my driving?) ❖ 17:56, 8 March 2007 (UTC)[reply]

Spiriling Mathematical Vortex Phenomenom - name??

Hello, and thank you for your time.

I am trying to find information about including the name of a naturally occurring phenomenon which I saw once and I know it is somewhat well known. This is a mathematically related phenomenom, nothing to do with drugs, spiritulality etc.

It is a kind of spiriling vortex, cone shaped, made up of geometrical shapes.

It's size is not fixed, but imagine an ice-cream cone with the bottom chopped off, except the 'cone', the solid part was made up of non-connected geometrical/mathematical shapes, with spaces in between. It was spinning slowly, and was transparent in that the geometrical shapes seemed to be made of yellow light.

There is a name for this thing, other people have seen it, (I even saw it in a VISA card TV commercial but didn't manage to record it in time) but if you go looking for "spiriling mathematical vortex" on the net you get a million hits about scientists discussing the movement of particles in vortexes, I can't find it in the mess, hence asking you guys who might know about it.

What I mean by geometrical/Mathematical shapes was something like the 3d blocks in the game 'block-out', like 3d tetris blocks, all different, but they all had some relationship with each other, so the whole thing gave the impression of forming a completed mathematical formula, sort of like if you represented the equasions of relativity geometrically.

If anyone knows the name of this thing or anything about it could you please email me at (email removed)

Thank you. (Email removed) (David J Ritter)(blucat) P.S. I don't care if my email address is public, I'm open, please publish it. —The preceding unsigned comment was added by 198.142.40.245 (talk) 08:54, 8 March 2007 (UTC).[reply]

is it based on the golden mean or similar?172.161.102.213 10:47, 8 March 2007 (UTC)[reply]

I'm going to go ahead and remove your email anyway, I'm pretty sure the rule here is not just if you 'care or not', we care:). Feel free to have your email on your user page, but not here please:). As for your answer, it's not some sort mandlebrot set ? Vespine 21:54, 8 March 2007 (UTC)[reply]

I think it's way more complicated than the golden mean. It seems to be on one scale only, so probably isn't a fractal thing. It may be some sort of mandlebrot set, but this is a specific shape, and has a seperate name. No one can get the Lance Henriksen VISA card TV commercial? Gives a computer sim and the name. Thanks, blucat. 198.142.44.82 17:38, 19 March 2007 (UTC)[reply]

Animal species: how do they self identify for mating?

I'm wondering how animals know what species to mate with? They don't know what species they are, so how do they recognise their own species to mate with? Thanks.Mjm1964 09:31, 8 March 2007 (UTC)[reply]

Phermones is related. How do they know what species to mate with? Well, how do you know what species to mate with? Would you mistake an orangutan for a sexy woman? Perhaps this is also related. [Mαc Δαvιs] X (How's my driving?) ❖ 10:13, 8 March 2007 (UTC)[reply]

Davis has a point. Humans are wired for facial recognition. I assume a dog is hard-wired to tell if a mammal is a dog, and which dog it is.

There are examples of subviral agents which transfer via conjugation of host and potential host.[9]172.161.102.213 13:12, 8 March 2007 (UTC)[reply]

Most animals use pheromone cues. For example, rodents have proteins in their urine (called Major Urinary Proteins or MUPS), saliva and tears that bind tightly to small volatile chemicals. The proteins are thought to stablise the chemicals so that their "smell" is held in urine (and the other excretions) much longer, allowing them to be sniffed by members of their own (and other) species. These chemicals and the proteins are sexually dimorphic, in that different sexes have different combinations (as do different species, obviously). Therefore by detecting and interpreting the "code" of chemicals and/or proteins from the urine, tears or saliva of other conspecifics, males can distinguish between other males (which they are genetically hardwired to fight) and females (which they are genetically hardwired to mate). Interestingly, the organ that detects pheromones, called the vomeronasal organ, is essentially missing in most Catarrhini, including humans. Its likely the evolution of trichromatic vision superceded the use of chemical cues to detect mates, and that is why we watch porn these days instead of smelling it. Rockpocket 04:41, 9 March 2007 (UTC)[reply]

Ductility of Uranium

See above...--Howzat11 11:18, 8 March 2007 (UTC)[reply]

Googling Ductility of uranium seems to suggest it has high hardness and low ductility making it difficult to roll out into foil. If you want more specific metrics, searching through some of those sites may yield an answer. Vespine 21:46, 8 March 2007 (UTC)[reply]

See Uranium for general information about the element, including its physical properties and see Ductility and Young's modulus . For another site giving the physical properties of elements see [10]. Uranioum is apparently a hard, heavy, and not very ductile element, but alloys could probably retain some of those properties and enhance the ductility. Compare to tungsten, which they found a way to draw into lightbulb filaments. Edison 13:23, 9 March 2007 (UTC)[reply]

Look mum! No hands!

Is it possible to masturbate without laying my hands on my manhood. Please do not answer back with "get someone else to lay their hand on your manhood." Prehaps I should change the question to Is it possible to ejaculate without touching your manhood. 220.239.111.36 11:47, 8 March 2007 (UTC)[reply]

It depends on how sensitive you are and how much time you are willing spend. For example dry humping can be done without using your hands and there are people who can masturbate and ejaculate with thought alone. A Google search turned up this site for more information on different techniques. - Mgm|^(talk) 11:54, 8 March 2007 (UTC)[reply]

Some women can orgasm just by thinking about sex. I don't think men are that lucky.172.161.102.213 12:43, 8 March 2007 (UTC)[reply]

This is known as Psycholagny, although WP doesn't have much of a page for it. —The preceding unsigned comment was added by 130.184.111.192 (talk) 13:13, 8 March 2007 (UTC).[reply]

see masturbation "A less common technique is to lie face down on a comfortable surface such as a mattress or pillow and rub the penis against it until orgasm is achieved"

It is possible to have an orgasm without any external movement or friction, by pulling on the muscle that controls urination and contracts during orgasm. I won't embarrass myself by trying to identify its proper name, but you probably get the idea. For this method, you will need lots of mental stimulation (usually your preferred type of pornography), lots of time (up to an hour) and lots of energy. Age is a factor as well. Mjm1964 13:27, 8 March 2007 (UTC)[reply]

Kegel exercises ? StuRat 16:55, 8 March 2007 (UTC)[reply]

There was a scene in American Pie I believe where it happened twice. Around that time someone claimed the same thing when meeting Brittney Spears in real life (this was back when she was 17). SakotGrimshine 15:32, 8 March 2007 (UTC)[reply]

It is theoretically possible for a man to orgasm strictly from direct prostate stimulation. --DrGaellon (talk | contribs) 17:35, 8 March 2007 (UTC)[reply]

See Frottage. Corvus cornix 22:31, 8 March 2007 (UTC)[reply]

I am skeptical of being able to orgasm at will without any stimulation. I don't think so. I'd like to see scientific evidence on that first! Ways to masturbate without "laying your hands on your manhood" would include: prostate milking/prostate massage, water pressure (say, from a showerhead, friction against other objects, and... I had a few more but this window was minimized for 5 hours and I forgot. Whoops! :) [Mαc Δαvιs] X (How's my driving?) ❖ 01:16, 9 March 2007 (UTC)[reply]

A wet dream would appear to meet the criteria (plus kudos for the question title, best in a while). Rockpocket 04:23, 9 March 2007 (UTC)[reply]

Aerosol Deodorant Cans

Are these still harmfull to the ozone? I usually refrain from buying them but a friend recently said that most companies "fixed the problem up".

I believe they have removed the CFCs, yes. But aerosol cans still aren't that good for the environment because they still release the propellant gas into the environment. Other types of deodorant are better, and pumps can be used for hair spray, etc. StuRat 13:22, 8 March 2007 (UTC) StuRat 13:20, 8 March 2007 (UTC)[reply]

Correct, no CFCs in anything now! They even changed my asthma inhaler recently so that it no longer used CFCs as a propellant. It was one of the few uses of CFCs left. --BenBurch 14:41, 8 March 2007 (UTC)[reply]

Most of the CFC's have been replace with HFC's which are still "global warming gases" but the mechansism that was proposed to explain ozone depletion only has chlorine as the destructuve chemical. There is still some concern however as the "ozone hole" has not reduced as expected since the reduction of CFC's and the models all had a very fast predicted recovery (it should have been very noticeable by now). --Tbeatty 14:58, 8 March 2007 (UTC)[reply]

There has also been studies that show ozone levels have rebounded, there being more than before, although that may have been me just looking at the certificate of stability[11]. Atmospheric ozone is measured in Dobson units, named for Gordan Miller Bourne Dobson, who invented the spectrophotometer, which was used to measure atmospheric ozone from the ground. There was a significant increase in the number of devices in 1956, when the Halley Bay anomaly in Antarctica was discovered. The anomaly however, was a November increase, in ozone levels over antarctica, this was three years before the big scare. To quote G. M. B. Dobson, "Forty years' research on atmospheric ozone at Oxford: a history," Appl. Opt. 7, 387- (1968) "the values in September and October 1956 were about 150 [Dobson] units lower than expected. ... In November the ozone values suddenly jumped up to those expected." Research is disputed over which bands of UV are more or less carcinogenic. De Fabo et al, Eureakalert, conflict for melanoma, and the 320-400 nm band UV is not blocked by the ozone layer, therefore, many would argue if we should even care at all, since it is all seasonal. Every instance of a visible ozone hole in the TOMS monthly average, has been in September. If that's not seasonal what is? [12][13][14][15][16][17][18] We also find exactly as much ozone that was missing in an "anti-hole," in, guess when? March! This reminds me of solstices and equinoxes [19][20][21][22][23][24][25]. The line looks pretty constant[26][27], although sometimes I wonder where the data went, with 2004 to 2005 changes like this[28][29]. So, there's the other side of the whole thing for you.

Spray Deoderant also has the problem of getting everywhere, probably costing more, and taking up more space than a stick. I heard to avoid stick deoderants with aluminum because it causes breast cancer even in men (and it happened to Isaac Hayes) -- this later may be incorrect at least as there's nothing in Isaac's wikipedia article, just something in the deoderant article about aluminum being a neurotoxin. SakotGrimshine 15:29, 8 March 2007 (UTC)[reply]

Oh please, when one study comes out that says something is carcinogenic that hasn't even gone through any peer review, that's called scaremongering. People love to share juicy scary stories and urban legends, and that's why this myth was perpetuated on the Internet so much. NCI [Mαc Δαvιs] X (How's my driving?) ❖ 17:40, 8 March 2007 (UTC)[reply]

Aluminium is carcinogenic? But most modern things are made from aluminium :) Althought there is a lot more cancer around recently :( HS7 19:15, 8 March 2007 (UTC)[reply]

Those ubiquitous "things...made from aluminum" are possibly not of an absorption-risk form such as might be the case with the aluminum zirconium in the product on the bathroom cabinet shelf, nor are they likely to be applied directly to [broken] skin. The warning to avoid the latter is displayed on solid (stick) deodorant/antiperspirant labels, such as on products produced by Procter & Gamble. Reputed carcinogenesis aside, I can recall (though without citation; sorry!) talk going back decades, of the aluminum in these products being implicated in the memory loss and similar brain damage associated with aging. -- Deborahjay 04:41, 10 March 2007 (UTC)[reply]

Physiology Videos

Just wondering if anyone could help by suggesting an sites/places(torrents) to get medical physiology videos? If they cover such topics as respiratory/nerve/muscle physiology etc.?

Much appreciated.

If there is a science torrent tracker site... *twitch* I want it! For text and audio, you can just type in "physiology torrent" in Google, Yahoo, The Pirate Bay [30] and Torrent Locomotive. But I actually have been searching for medical science videos recently, and found nothing. Any help would be doubly appreciated.[Mαc Δαvιs] X (How's my driving?) ❖ 17:50, 8 March 2007 (UTC)[reply]

I would suggest you do a search for Opencourseware looking for physiology courses. For example, Berkeley University have done an excellent videoed general human anatomy course that includes some physiology, although probably not in enough depth for you. But other universities are also videoing lectures and putting then on the internet. Hexane2000 06:50, 9 March 2007 (UTC)[reply]

A moon of a moon

Would it be theoretically possible for a moon to have a moon of its own? Say, something the size of Phobos orbiting something the size of Ganymede orbiting soemthing the size of Jupiter? Battle Ape 14:11, 8 March 2007 (UTC)[reply]

When the Apollo crafts orbited the moon, they were satellites of a satellite. Just imagine a rock the same size as one of those ships. — BRIAN0918 • 2007-03-08 14:13Z

Entirely possible. The question is how stable are those orbits over millions of years? And the answer is "not very". This is why we don't see any moon-on-moon action here in our solar system though I would venture a guess that there HAVE been moons of moons during its history, and will be again. --BenBurch 14:40, 8 March 2007 (UTC)[reply]

It's worth noting that this isn't a terribly different scenario than a Sun-planet-moon system. The key consideration (discussed at n-body problem) is that the smallest body must have a mass insignificant with regards to the largest body. It's also worth noting, while we're on the subject, that the Sun-Earth-Moon system doesn't meet this criteria. Isaac Asimov notes (I believe in The Double Planet) that the Moon's orbit, observed from the Sun, is always concave about the Sun, a characteristic not shared by any other moon but shared by every other planet / minor planet. Some basic discussion of this can be found at [31], [32]. It's not directly relevant, but it may be interesting. — Lomn 16:19, 8 March 2007 (UTC)[reply]

Did you mean "the Moon's orbit, observed from the Sun, is always concave about the Sun"? Have I misunderstood what you mean by 'concave'? Surely what is special is that the Moon's orbit never doubles back on itself. It still has to be convex (if I understand how you're using concave) sometimes, as the Earth and the Moon orbit the sun with their paths 'weaving'. Both the Earth and the moon have to have a 'convex' orbit sometimes. Skittle 01:13, 9 March 2007 (UTC)[reply]

Certainly the Moon is at times closer to and at times farther away from the Sun. But because it orbits so slowly, the Earth's orbit bends the "sine wave" back on itself such that it's always curving towards the Sun, just about half the time it's turning less tightly than is necessary to maintain its distance. This curving is what's meant by "concave" in this context. (It's concave because the Sun is on the inside of the curve.) --Tardis 14:39, 9 March 2007 (UTC)[reply]

Moon on moon action. Nice. —The preceding unsigned comment was added by 199.197.124.144 (talk) 16:57, 8 March 2007 (UTC).[reply]

A similar situation may be where the smallest object is in a Lagrange point relative to the two larger objects, specifically Lagrange points 1 and 2. StuRat 16:34, 8 March 2007 (UTC)[reply]

This question came up not so long ago... You might want to check the archives for the past couple of weeks. SteveBaker 16:54, 8 March 2007 (UTC)[reply]

That was the question I asked :) Don't bother looking in the archives, I got the same answers as those above :( HS7 19:13, 8 March 2007 (UTC)[reply]

about the PTSD

what this the risk factor of this post traumatic Stress Disorder?how about the clinical picture of it? —The preceding unsigned comment was added by 196.218.135.2 (talk) 15:59, 8 March 2007 (UTC).[reply]

The Wikipedia page conveniently titled Post Traumatic Stress Disorder is a good place to start. I assume you searched the website before asking on the Reference Desk, right? DMacks 16:05, 8 March 2007 (UTC)[reply]

Looking for source

I've found there's an entry for Paul L. Kirk in volume 56 of the "National Cyclopedia of American Biography", but unfortunately my local academic library doesn't cary it. Can someone who has access send me a copy of the text and the info I need to properly cite the book? On a side note, I know of the existence of Wikipedia:Newspapers and magazines request service. Is there a similar service for books? - Mgm|^(talk) 16:56, 8 March 2007 (UTC)[reply]

Calculating errors

I've got several sets of experimental data, and am trying to find the total error inherent in reading this. I've found the pressure acting on an area using a millimetre-graded ruler and an accurate forcemeter, so the error inherent in the ruler is ±0.0005 m, while the error measuring the force is ±0.005 N. However, when I find the confidence in the pressure readings by the formula p=F/A, I get ±20000 Nm^-2, which is way larger than any readings taken! Surely the experiment cannot be this inaccurate, given that all the results form a good line of best fit. Laïka 17:29, 8 March 2007 (UTC)[reply]

[33] might be useful, specifically the final formulas at the bottom of the Multiplication and Division sections. It's the same way I've been taught to do it in my first-year Physics course. -- Consumed Crustacean (talk) 17:40, 8 March 2007 (UTC)[reply]

[34] would be my recommendation. Basically if C = A / B and you know the error in A is eA and the error in B is eB then the error in C (eC) is given by: (eC/C)² = (eA/A)² + (eB/B)² - so the magnitude of the error depends on the magnitude of the data. This means that strictly you need to calculate the error bounds for each data value - although in a lot of scientific endeavors, it's enough to plug in 'typical' values for A, B and C to get an idea of the 'typical' amount of error - since your error terms are somewhat estimated anyway. (eg: If your millimeter ruler is not temperature-compensated then the result you got using it depends on the temperature when you used it - that adds more error that you hadn't included in your estimate). SteveBaker 17:53, 8 March 2007 (UTC)[reply]

Thanks for those links; they've helped a lot! Laïka 21:01, 8 March 2007 (UTC)[reply]

Broken solar water heaters

Does anyone here know of a way to find cheap broken flat plate collectors to use for an experiment/project? I have already tried eBay. -User: Nightvid

Maybe you can build one from scratch. It should just be a hose, some plexiglass, and a bunch of insulation, in a box. Or you can look at Froogle. Nimur 18:54, 8 March 2007 (UTC)[reply]

The experiment I am working on is about the potential for modified low-tech (non-evacuated, non-concentrating) solar collectors to reach temperatures in excess of 200 or 220 degrees Celsius (with no water of course). I need something like at least the parts or pieces of parts (fragments) for a commercial collector, but on a two-digit (USD) budget. Plexiglass and most other plastics melt at too low a temperature for my purpose. -User: Nightvid

how about a large dish made from metal that would focus the sunlight onto, say, a cooking pot or something? Think outside the box 12:58, 9 March 2007 (UTC)[reply]

Apparently you didn't notice that I said 'non-concentrating'. -User: Nightvid

The 200 C and 220 C temperatures you specify are pretty high for low-tech non concentrating solar panels I have seen over the past several decades. Then you want it to be cheap. You need a material on the sun side which lets the solar energy in (around one kilowatt per square meter) and does not allow the infrared to radiate back out. Cheap lowtech front panels let the IR radiate out, limiting the max temp. Then the energy has to hit something like a flat black painted metal surface to absorb the energy, then it needs a very high R value insulation on the back and sides, which is able to withstand the high temperature specified. The tiniest air leakage or lack of a uniform high R value thermal insulation dramatically lowers the temperature. You did not specify if the goal was to heat air, water, or some other working fluid, or if you proposed to use this device as, say, an oven for cooking or other processes. You want 220 C or higher, which would obviously be able to generate steam to run a steam engine. It generally gets hardeer and harder to achieve higher and higher temperatures. Good luck. If you succeed I want one too. You might contact companies which manufacture solar panels, such as [35] and see if they sell rejects or blemished panels at a discount. Sometimes manufacturers have products which have cosmetic problems and they would sell them rather than invest more time in attempts to correct the blemish, or they might fail quality control but still be somewhat useful to an experimenter. Their concern in selling thim would obviously be that they would not want a purchaser to then demand that the devices perform like ones sold at full price, and they might want to be sure that the purchaser of blems or rejects does not then try to sell them in competition with the manufacturer or its normal sales outlets, or does not reverse engineer the product and start up a competing manufacture. Edison 15:56, 9 March 2007 (UTC)[reply]

I have a device that works too well. In fact you will need some arrangement for automatic thermostatically controlled venting. I want to patent the device but have the same problem as to funding. I can only share it with you under a non-disclosure agreement and a venture capital commitment so that I can get the patent. Sorry but I want to get married and raise a family without subjecting them to the poverty I'm likewise in. Max temperature of the device at solar noon clear sky is 350 Fahrenheit. Construction materials are as cheap as they get but without automation somewhat labor intensive. Let me know. 71.100.166.228 18:17, 10 March 2007 (UTC)[reply]

Great advice! I have contacted the SolMaxx folks just now. Currently, my project is merely "proof-of-concept", although I would at least try to use it to make/mold plastic items with. The first device I attempted to build, at home in less than one day, did just that (read: self-destructed).

The second thing I built gave me a measured internal air temperature of almost 150 Celsius (on a cold day, too!), and could've been much higher if I could've spent more time on it or had the right parts. (150 C isn't bad for a non-concentrating solar device built in under an hour, is it?) As far as venting is concerned, I am trying to avoid that need due to expense and complicatedness. This is precisely why I am seeking materials that can take the heat.

Good luck on getting your patent some day. -User: Nightvid

Maybe you could put a car in the sun and close all the windows. That'll heat up pretty good. Warning: Do not lock pets or babies inside a hot car (or inside your device) [36] [37] [38] [39]. Nimur 20:32, 11 March 2007 (UTC)[reply]

First commercial portable data projector?

Middle school teacher (and his student) getting lost in too many types of data projector for research project, having trouble figuring out when the first portable data projectors hit the market, and related ideas -- cost, etc. Anyone help us find our way to the relevant article? Thanks... Jfarber 18:49, 8 March 2007 (UTC)[reply]

Overhead projector? Perhaps you mean projector...? Nimur 19:05, 8 March 2007 (UTC)[reply]

We do indeed mean the latter -- the computer projector. Sadly, however, there is no HISTORY section in that disambiguation page, and there's no single page about the type of thing we're looking at, as there would be in articles about other objects / object types which have evolved over time. The closest I can find is this section of the LCD Projector page -- but while the section is labeled "history", there are no real dates here. The article needs to be overhauled, I'd say -- I'd even vote for a page about computer/digital data projectors instead of the disambig page -- but in the short term, the student would like some help finding the relevant historical/timeline-esque information. When did the first data projector that was NOT for use with Overheads hit the market? When did they become portable? Who was first? Heck, even a google search of "first data projector" only finds company-specific examples...is this really so rare a tpic that there's no good history out there? Jfarber 19:10, 8 March 2007 (UTC)[reply]

I fear you will need to do original research on this one. Go to a library and look at back issues of PC Week or a similar magazine and check the advertizements. Step back in one-year increments (e.g., look at the first issue each year.) You may get lucky and find a feature article in PC Week also. -Arch dude 21:37, 8 March 2007 (UTC)[reply]

It would be easier, in my opinion, to find the patent of a current projector and then step through the patents it references on Google Patents. --140.247.252.156 21:58, 8 March 2007 (UTC)[reply]

Last call...Really? No one? Interesting that such an obvious and ubiquitous object in modern culture would have none of the information usually associated with other evolving technologies in its Wiki-presence. The topic isn't that obscure -- every business or educational setting I've encountered in the last decade knows what these things are, and covets more.

I don't think it's 7th grade-level work to ask my student to sift through old magazine archives, nor do I think she'd make much sense of Google Patent, though that was a great idea, and thanks for it. I guess if no one else steps forward, we'll make the teachable moment work for us. In the long run, maybe I'll do the research and write the entry -- I can't be the only one out there who would find this information useful. Jfarber 00:45, 9 March 2007 (UTC)[reply]

The first consumer-level designs that I was aware of were not complete, self-contained projectors. Instead, they were liquid crystal display cells that sat over an ordinary overhead projector. They were usually fan-cooled. I'm pretty sure I remember them being popular in the late 80s.

Before that, data projectors were either giant CRT affairs or, rarely during my lifetime, Eidophor systems.

Atlant 11:58, 9 March 2007 (UTC)[reply]

That is helpful, Atlant, thanks -- though I was still a student in the late 80s, and not yet a teacher, I remember learning from such displays fondly, and also remember seeing them in use in my early teaching days (early-mid nineties) in those schools not yet lucky enough to have the funds for true stand-alone computer-interfaced projectors.

We are still hoping for some information which would fill the gap between then and now, however -- for example, on when self-contained projectors showed up, and when they became portable. Or even when they started projecting color would be helpful. So much (surprisingly) missing in our entry, and int he cultural knowledge pool... Jfarber 14:03, 9 March 2007 (UTC)[reply]

As to how far back to look, Don Lancaster published plans for a TV Typewriter in 1973 with improved kits available in 1975 with a serial input, so the technology was there to convert ASCII to video on any TV screen. By about 1975 people had home built "portable" computers. By 1981 there was the Osborne and by 1982 the Kaypro, commercially made 29 pound or so portable computers (hardly laptops). Then see " Movies in the Sky with V-Star 3 " Rosenberg, Hilary. Financial World. New York: Aug 31, 1983.Vol.152, Iss. 15; pg. 29, 2 pgs obtained (subscription) from Proquest.comSays that airliners had video projectors for inflight movies and the V-Star 4, was a land-based version of the inflight V-Star 3, which could be used with computer systems for teleconferencing. The article said that competitive data projector systems cost $60,000, but the . The V-Star 4 could be had for $13,000. It was manufactured by Barco Electronics of Belgium. You can see the inflight version at E-Bay at [40] and it is clearly portable, being no wider or taller than the lenses, and way smaller than the earlier Advent video projector. I expect that like any invention there would be competing claims to the invention based on some tinkerer interfacing his 1974 Altair home build computer to a portable TV, then putting a projection lens in front of the TV, and projecting data onto a screen for a science fair or computer club meeting in 1975, or perhaps doing the same projection lens in front of the portable 1950 TV or oscilloscope and somehow hooking it up to a primitive analog or digital computer of that era to display some sort of output. You have to decide when something is "invented" on a basis of commercially available, or simply reduced to practice, or impractical but showing the basic principle, and then there are the wild claims of people that they invented the thing decades ago but the invention was stolen or suppressed.You specified "commercial" which helps to eliminate the first efforts. So now the trick is to see if there was anything prior to the Barco Vstar 4. There were certainly earlier commercial video projectors, and I saw them set up and removed for special showings like an away football game broadcast on TV by 1970, but it took a couple of guys to haul it in and out. Someone somewhere could have used one of those for data projection in the early 1970's. "In-Flight Movies Update Content and Equipment" By Aljean Harmetz, New York Times Apr 27, 1982. pg. C11, 1 pgs says that as of that date there were 465 airplanes with video projectors for inflight movies. The first New York Times story about video data projectors was "Who Lives by Technology Dies -- Slowly -- by Technology; Portables are so useful when giving speeches -- but only if they work. by Peter H. Lewis. New York Times Aug 16, 1992. pg. F10, 1 pgs . It said that "the latest" LCD projectors with their own light sources, capable of photo quality video and data projection, for connection to computers, cost $6,000 to $8,000, and mentioned the earlier LCD projectors which went on the screen of an overhead projector. Edison 20:50, 9 March 2007 (UTC) "Edison 16:32, 9 March 2007 (UTC)[reply]

Thanks, Edison. This was a great response, clear, dense, and very helpful (though I did need to help the student in question figure out why laptops were so important to the answer -- certainly having a portable projector doesn't necessarily mean having a portable computer!). Jfarber 01:21, 11 March 2007 (UTC)[reply]

Does size matter?

My friend says that larger bananas have been forced to grow to that size and therby spread their nutritional value through a larger mass. Thus she says a smaller banana is better value since it contains the same quantity of vitamins but weights less and therefore is cheaper. Is this true? --Seans Potato Business 19:24, 8 March 2007 (UTC)[reply]

It's true smaller bananas are generally cheaper, but to grow larger a banana needs more nutrients, so it wouldn't be spreading the same amount of nutrients through a larger mass. - Mgm|^(talk) 19:51, 8 March 2007 (UTC)[reply]

Experiment time: if sugar is considered a nutrient, then the smaller banana should taste sweeter than the larger one. Does it? --Bowlhover 21:33, 8 March 2007 (UTC)[reply]

I wouldn't say "larger bananas are forced to grow to that size." That sounds like "baby ducks, bunnies, and pandas are forced to.." jeez! The bananas got to their size and taste through genetic engineering and selective breeding. There are also, different kinds of bananas that taste different. [Mαc Δαvιs] X (How's my driving?) ❖ 22:02, 8 March 2007 (UTC)[reply]

Also, a larger banana has a greater ratio of flesh to peel, so I would say that larger bananas are a better value, if they are sold by weight. ^tucker/_rekcut 22:32, 8 March 2007 (UTC)[reply]

I've heard the phrase 'force-grown' quite a lot in newspapers, etc. It seems to be used to mean 'grown artificially out of season' - at least, that's what a quick google and our force (disambiguation) page say. I can't find a good source to lend some authority and detail, though. I'd assume that it means that the food is grown with fertilizer for its size and appearance, rather than in good soil for taste and nutrition. I don't think it's a rigorously defined term. --HughCharlesParker (talk - contribs) 22:49, 8 March 2007 (UTC)[reply]

Ah, I see. Thanks for that. [Mαc Δαvιs] X (How's my driving?) ❖ 23:55, 8 March 2007 (UTC)[reply]

Some fruits have chemicals sprayed on them to make them ripen after they have been picked, maybe this was what they meant :) I don't think it would make them grow much, but since the fruit isn't ripe when it is picked, it might have less nutrients in :( HS7 20:05, 9 March 2007 (UTC)[reply]

Bear in mind, too, that there are different varieties of banana grown and marketed, and that the size of the mature fruit is one of the characteristics that may vary from one type to another. (You're probably more familiar with commercially available varieties of apples, for example, that differ in sweetness and flavor as well as color and shape, etc.) Check with your local growers' board, or the Department/Ministry of Agriculture for your country, for information on the relative nutritional qualities of the bananas available to you. -- Deborahjay 04:29, 10 March 2007 (UTC)[reply]

separate populations and species

i am look for information that can help me answer a question. Factors can separate population and species —The preceding unsigned comment was added by 208.233.37.66 (talk) 20:41, 8 March 2007 (UTC).[reply]

Well, it sounds more like a statement more then a question but the answer is definitely "Yes", factors can indeed separate population and species. Information that can help answer that 'question' can most likely be found in the speciation article. If you mean What factors can separate population and species", then that article will still help.Vespine 21:26, 8 March 2007 (UTC)[reply]

March 9

info photocopiers

Where can I find out how to construct a primitive photocopier? Nate Bernhardt 00:32, 9 March 2007 (UTC)[reply]

Here is one built out of Lego...it's pretty darned primitive! http://mindstorms.lego.com/eng/inventions/image.asp?img=14155image1.jpg

But it doesn't work anything like a real photocopier does. These days you might as well use a computer scanner and a printer. SteveBaker 01:26, 9 March 2007 (UTC)[reply]

If your interest is in finding a primitive way of copying, rather than a primitive version of a real photocopier, and you're not planning on using the copies for anything important, you could try using jelly. I've never actually done it myself, but I think you set jelly in a tray (it may have to be more or less wobbly than normal), you write/draw what you want copied (perhaps with a particular kind of ink), you carefully place the original on the set jelly and run a roller over it, to transfer the ink to the jelly. Remove the original, then place a clean piece of paper on the surface of the jelly and roller it. Skittle 17:17, 9 March 2007 (UTC)[reply]

It might be easier to set up your own printing press and just engrave what you want in metal and cover it with ink, so you can make as many copies as you want without spoiling any jelly :] HS7 20:02, 9 March 2007 (UTC)[reply]

Plane refuelling

File:Flight.JPG

When you have two planes of different size that have just refuelled, with a photo taken from above, and the planes no longer overlap, how can you tell which was the source of fuel? Is it always the larger plane providing fuel for the smaller one? Or is the one in front always providing the fuel? (that would mean there is a rule that you cannot directly "overtake" your refueller, only veer away from it sideways) Thanks for answers. Samsara (talk • contribs) 00:47, 9 March 2007 (UTC)[reply]

You mean with in-flight refuelling? Generally the larger one is the tanker - and the small one is a fighter or a smaller bomber or even a helicopter - but (as you can see from the photo) they refuel C-5 Galaxies (the largest American military transport and one of the largest military aircraft in the world) from a KC-135. The Galaxy has a wingspan of 222 feet and a length of 247 feet - the KC-135 is just 136 feet long with a wingspan of 131 feet. So you certainly can't go by size if both aircraft are bigger than maybe 100 feet across. When they are transferring fuel, the plane in front is always the one supplying the fuel - but you said that you needed to know this after they have separated. Generally the aircraft that just refuelled falls behind and does a diving turn away from the tanker - but if the aircraft that just got a fill up is a fighter - it might well dive below and then out-accellerate the tanker - so once they are safely separated, it could easily wind up in front. Is there a particular reason for your question? Maybe I can offer more help. I design flight simulators for a living - we do a lot of training of US and other airforce pilots - and that includes in-flight refuelling exercises. I've actually done the manouver several times in our simulators - it's pretty scarey. SteveBaker 01:06, 9 March 2007 (UTC)[reply]

I'm not much of a virtual pilot but I've tried to do the manouver in Falcon 4.0 a couple of times, haven't managed to nail it yet. Even a simulator gives you a good appreciation of the surgical like precision with which fighter pilots must control their multi ton multi million dollar super sonic vehicles... As to the question, the one with the dangly thing is usually the source of the fuel. ;)Vespine 01:17, 9 March 2007 (UTC)[reply]

Yes, I can get a screenshot. Hang in there. Samsara (talk • contribs) 01:17, 9 March 2007 (UTC)[reply]

See above. Samsara (talk • contribs) 01:23, 9 March 2007 (UTC)[reply]

If you think it's tough in a fighter - you should try it in a helicopter! (Hint - you really don't want to hit the boom with your rotors - and the tanker is flying so slowly it's about to stall out and your poor helicopter is going absolutely flat out...which isn't good when you are low on fuel!) The manouver is actually quite a bit harder in a simulator than in reality because you don't have the depth-perception cues to get you accurately aligned with the refuelling probe - and on a PC-based simulator, your lack of peripheral vision is kinda annoying. The main hint I would give you is to pay attention to the 'director lights' underneath the tanker - they guide you into the right flight path and speed - then you just have to use a light touch on the stick to get the probe into the drogue. SteveBaker 01:32, 9 March 2007 (UTC)[reply]

Actually, that's just reminded me of this great video I saw ages ago, didn't take a lot of looking to find it. Pretty amazing and I bet a little scary! Vespine 03:29, 9 March 2007 (UTC)[reply]

Google video says that the video is "Not currently available" - but if you search for 'Refuelling accident' you can find it on YouTube.com ...but WOW! That was unexpected. The guy clearly over-compensated for a small initial error...but the consequences were not at all what I guessed they would be! He was lucky not to lose a rotor blade - but he may yet have dinged it so badly that the vibration would trash the rotor head bearings. Wow! SteveBaker 16:17, 9 March 2007 (UTC)[reply]

Artificial life

I was watching a lecture by Peter Ward (The Undesigned Universe: Part 3: The Construction of the Cosmos) here [41] and at 33:34 into it, Ward mentions something about a scientist who is trying to build artificial life and got a grant from Princeton University to do it. I can't make out his name when it's mentioned from the video. Does anyone know who he mentioned? Imaninjapirate^{talk to me} 03:11, 9 March 2007 (UTC)[reply]

This [42] artificial virus (a bacteriophage) was made in 2003. There is some debate about whether viruses should be considered 'alive' - but this one does reproduce. The same guy is trying to do the same thing with a bacterium [43] SteveBaker 03:25, 9 March 2007 (UTC)[reply]

Question regarding bacteria.

I have heard somewhere that simple celled animals (like, say, amoeba) can't grow larger than a quarter than starving themselves. Does this apply to bacteria? Raptor Jesus 04:08, 9 March 2007 (UTC)[reply]

Yes, because bacteria only have one cell. Unicellular organisms can, however, grow much larger than you might expect by becoming extremely skinny. --Bowlhover 05:22, 9 March 2007 (UTC)[reply]

Hmm... then how could bacteria evolve into an organism, if the theory is correct? Raptor Jesus 06:03, 9 March 2007 (UTC)[reply]

Bacterial colonies, very likely.--Pharos 06:23, 9 March 2007 (UTC)[reply]

Bacteria ARE organisms. --Ķĩřβȳ♥ŤįɱéØ 01:00, 10 March 2007 (UTC)[reply]

Bindeez

How do Bindeez work (the colourful beads that join together with a spray of water, sold as a kids art toy)? The websites I go to don't give me any explanation for their joining-together-with-water abilities other than "magic". --Candy-Panda 05:59, 9 March 2007 (UTC)[reply]

Well, that's because it is magic; what more did you expect? [Mαc Δαvιs] X (How's my driving?) ❖ 07:04, 9 March 2007 (UTC)[reply]

no idea! i never knew something like that existed! Think outside the box 12:14, 9 March 2007 (UTC)[reply]

But seriously, it would help if we could have a little bit more information on what happens (i.e. you have to wait for it to dry, it takes about five seconds, it is instant) then we could probably figure it out. Are they made of plastic? [Mαc Δαvιs] X (How's my driving?) ❖ 16:23, 9 March 2007 (UTC)[reply]

I've seen them sold alongside Hama beads (the ones you iron to melt together). The packaging suggests that simply spraying them with water does it instantly, although I've never used them myself. I would suspect that it's a bit like those cornstarch bead things, that the outside of beads dissolves slightly, making them sticky to each other. But I don't know. Skittle 17:08, 9 March 2007 (UTC)[reply]

well from my experience I would say that it may be some kind of unsaturated fat/oil because oils tend to congregate as beads and come together to form a larger mass. But as for the spraying the water part? to me that doesn't make too much sense, maybe the oils have been altered in some way and need to be hydrated? >.<

-maxx- Maxx4444177 18:37, 9 March 2007 (UTC)[reply]

They could be patented, so that you aren't allowed to find out :( Would looking at them under a microscope help :) HS7 19:57, 9 March 2007 (UTC)[reply]

Actually, patenting works exactly the opposite from that: you look up the patent application, and it tells you how it works. You just aren't allowed to use that information to make it yourself until the patent expires. --Carnildo 20:56, 9 March 2007 (UTC)[reply]

http://patents.google.com ! [Mαc Δαvιs] (How's my driving?) ❖ 23:32, 9 March 2007 (UTC)[reply]

Rise in temperature

Why is there a rise in body temperature after keeping small onions under the armpit for sometime??? —The preceding unsigned comment was added by 59.92.19.220 (talk) 09:25, 9 March 2007 (UTC).[reply]

I think the real question is, why are you keeping small onions under your armpits for sometime? --Candy-Panda 10:41, 9 March 2007 (UTC)[reply]
- embarrisment? Think outside the box 12:10, 9 March 2007 (UTC)[reply]
  - Damn, do you really smell that bad that you have to try and roast onions to cover up the smell? [Mαc Δαvιs] X (How's my driving?) ❖ 16:24, 9 March 2007 (UTC)[reply]

Jerking off without using your hands, keeping small vegetables under your armpits!!! I guess we're all freaks & wierdos eh?

I don't think we know, if that is even true at all. [Mαc Δαvιs] X (How's my driving?) ❖ 16:24, 9 March 2007 (UTC)[reply]
The only reference to it I can find is on Snopes (the urban legend debunking site) - but it's a bit confusing and there is no conclusive end to the debate: http://msgboard.snopes.com/message/ultimatebb.php?/ubb/get_topic/f/42/t/000261/p/1.html - I'd be very surprised if this were true. The body is very carefully set up to control body temperature and I doubt that enough of any sort of chemical from the onions could leach through the skin to change that by any measurable amount. I call "Urban Legend". SteveBaker 17:48, 9 March 2007 (UTC)[reply]

Hole punch things

What are the pieces of paper that are punched out using a hole punch called? Thanks, Bioarchie1234 10:27, 9 March 2007 (UTC)[reply]

If they are colourful, Confetti? --Candy-Panda 10:43, 9 March 2007 (UTC)[reply]

Chads. --BenBurch 10:45, 9 March 2007 (UTC)[reply]

Chad (paper). --hydnjo talk 15:57, 9 March 2007 (UTC)[reply]

well for complete lack of a better word (and so as not to make those around you feel stupid) lets just call them little paper hole punch circley thingeys -maxx- Maxx4444177 18:24, 9 March 2007 (UTC)[reply]

clinical medicine

pls i want to know more about clinical medicine,and its development so far. —The preceding unsigned comment was added by 195.166.234.42 (talk) 11:40, 9 March 2007 (UTC).[reply]

Oddly, our article on Clinical medicine is pretty much useless - which is surprising because we have an entire WikiProject dedicated to the subject. I suggest you start reading there: Wikipedia:WikiProject Clinical medicine. There is a navigational template at the very bottom of that page that links to bunches of useful material. You might want to discuss your studies on the 'discussion' page there - I'm sure the folks at the project will be able to get you onto the articles you need. SteveBaker 17:37, 9 March 2007 (UTC)[reply]

Bacteria pathogens with short incubation period

Hi, Could someone please list all bacteria pathogens that have incubation period shorter then 24 hours (except Pasteurella multocida). I'm not looking for foodborne bacteria, but bacteria that infect soft tissues, like infection that occur after skin cut. (I have searched for such a list but haven't found anything other then Pasteurella multocida). DanB88 12:16, 9 March 2007 (UTC)[reply]

Some of those 'flesh eating' bacteria (Necrotizing fasciitis) work pretty fast. The article says that 'progression is within hours' - and these are certainly infections of the soft tissues and can sometimes come from some sort of skin trauma (although the article says that a sore throat is a more common first symptom). RTFA dude! SteveBaker 17:31, 9 March 2007 (UTC)[reply]

well as for listing all of them that request will be short lived, as there are many more bacteria tthat havent even been discovered yet, although i do know that stapholococcus (sp?) have a relatively quick incubation rate.Maxx4444177 18:47, 9 March 2007 (UTC)[reply]

-maxx-

Why? In the evolutionary sense...

This is really 3 qestions so 1)The Naked Ape, why of all primates, do we have the least amount of body hair? 2)Why do human males have the largest penis's in relation to body size of all primates? Sexual selection (so size does matter!)? 3)Why do some fish, such as muskelunge and pike reach old age, senessence? I've asked this 1 before but never really got an answer. I was even called narrow minded to think that every gene is subject to selection but, to my narrow little mind that seems dismissive. I'm just curious as to your opinions/theories. 216.209.110.32 12:38, 9 March 2007 (UTC)Canis sylvaticus[reply]

1- humans have less hair because they wear clothes and so the need for exsessive body hair has gone
2- maybe because there is less hair the penis has become lager to keep warm in winter.
3- all things age because mitosis, the replecation of DNA is not always perfect. When cells are made they are copied from previous one. So if a cell were damaged, they copy the damaged cell aswell. Think outside the box 12:46, 9 March 2007 (UTC)[reply]

Here's another hypothesis from somewhere: since having too much hair and wearing heavy clothes makes one itchy, and makes the body more likely to retain sweat and sweat-smells (since such things cling to the hair), and because lots of hair can cause one to retain things like fleas which can often live inside clothes, perhaps cultures which demand more heavy clothes-wearing are ones in which there is less body hair. Think outside the box 12:53, 9 March 2007 (UTC) thank Jfarber for that.[reply]

Thanks...BUT... 1)So which came first? The wearing of clothes or the loss of hair? What few examples we have seem to indicate that clothing is minimal at best, so your argument doesn't really hold water. Similarly, retention of scent need not be detrimental to reproductive success or survivibility though certainly BO is not currently in favour. I could almost buy the parasite argument except that, as you concede, parasites can and do exist in clothing. 2) Plausable but this would require that our own evolution occurred in a clime that was colder than that of our fellow apes. 3)Perhaps I haven't made myself clear in my Q. What possible advantage could there be in surviving beyond reproductive age as is the case with Muskie & pike? There is no parental care in these species nor do they school. The only advantage I can imagine is that they somehow are selectively cannibalistic, eating or, at least making it more difficult for the offspring of thier competitors to survive. 216.209.110.32 13:23, 9 March 2007 (UTC)Canis sylvaticus[reply]

The Naked Ape, why of all primates, do we have the least amount of body hair?
Well, clearly we don't need it or evolution would make us have it. We do actually have hair over much of our body - it's just become very short, fine hair that's hard to see. It even stands up when we are cold ('goose bumps') in a vain effort to trap some air within it - just as if we were still much more hairy. That suggests that we lost the denser hair of our nearest relatives relatively recently. Since humanity did most of it's evolving in tropical climates - and we'd learned to make primitive clothing at around the time we migrated north into colder climates - it's no so surprising that we don't have much hair.
Why do human males have the largest penis's in relation to body size of all primates? Sexual selection (so size does matter!)?
I suspect it's more to do with our upright walking stance and (in consequence) the mating postures we take...but I don't know for sure.
Why do some fish, such as muskelunge and pike reach old age, senessence? I've asked this 1 before but never really got an answer.
Probably they look after their young for longer than other fish. I don't know for sure. Humans (for example) are able to live much longer than is necessary for us to pass on our genes to the next generation - and that's a bad thing for survival in general because it means that there are all of these older people eating the food that the kids could need to survive - but because of our big brains, children take a ridiculously large amount of time (compared to ANY other animal) to get to the point where they can survive alone - so there is a huge evolutionary benefit to us living long enough to see our children into at least their teens. The same MIGHT be true of these fish - but I think you'd need to be some kind of a fish biologist to know for sure.

SteveBaker 16:06, 9 March 2007 (UTC)[reply]

See [|NYT] for some recent suggestions on human hairlessness, but I don't think this is a solved problem. Hairlessness seems to predate wearing clothes. It may have more to do with freeing the body of parasites (only minimal clothing is needed in our hot evolutionary environs, so there is probably a significant net reduction in parasites), or perhaps heating/cooling issues related to an erect posture in a hot climate.

I think penis size is also poorly understood. There is, however, good data relating the ratio of testicle size to body mass in primates based on sperm competition - how likely a female is to be promiscuous in a given troop structure. --JPFlip 16:17, 9 March 2007 (UTC)[reply]

Regarding 1), I've heard that the loss of hair might be an adaptation to moving out of the forest and into the savannah. In the already warm climate of tropical Africa, the loss of hair could have helped aid a more active lifestyle by improving evaporative cooling. A lot of hair would trap heat and sweat near the body's surface. I also understand that we are substanitally more prone to sweating than other primates. Evolutionarily speaking many of the changes in homonids over time seem promote the ability to run for prolonged periods and this kind of sustained activity may have been a necessary part of life on the open savannah. Also our ancestors appear to have made at least some controlled use of fire for longer than there have been homo sapiens [44]. Given the climate and these other factors, it may have been that being able to keep cool was a greater evolutionary advantage than the traditional value of having fur for keeping warm. Dragons flight 16:26, 9 March 2007 (UTC)[reply]

Well, I know a lot of people don't like this theory (I don't really understand why), but the best explanation for human hairlessness I've seen (the only one that makes sense to me) was explained in The Descent of Woman, and later in The Aquatic Ape. Basically, humans have little fur, but we do have a layer of blubber under our skin. If we lost the hair to keep cool (an explanation I've seen), or because we wore clothes and so didn't need fur any more (which is seriously twisted logic!), why would we gain the layer of blubber? Note: furry mammals don't have a layer of blubber. A layer of blubber is a typical feature of a mammal that lives in the water, as it keeps you warm better when wet, without weighing you down. Add to this the way the hair lies on your body, the way the hairs run in towards your spine rather than straight down your back, and it really does look like our ancestors took to the water at some time in the past. It also explains a lot of other stuff, but you'd do best to read a book on it for that info. 86.140.175.30 16:29, 9 March 2007 (UTC)[reply]

Elaine Morgan Skittle 16:32, 9 March 2007 (UTC)[reply]

I'd propose penis size is so out of proportion because we stopped having to worry about part of it being ripped off and completely losing function. We were so far ahead we were more leisurely, and that gave us room for each other's sexual turn-ons to get better and better because the people that weren't as sexy died. [Mαc Δαvιs] X (How's my driving?) ❖ 16:29, 9 March 2007 (UTC)[reply]

Hypothesese (sp) I've heard for penis size have tended to focus on 1)sexual position demanded by an upright posture altering the female form and 2)promiscuity, in that more promiscuous species tend to have longer penises (among other things) to try to get their sperm to the egg first. Skittle 16:35, 9 March 2007 (UTC)[reply]

I'm not suggesting that we lost hair because we wore clothes - that would be seriously twisted logic! No - I'm saying that in Africa we didn't need hair (or clothes for that matter - people who live in the wilds of Africa, Australia or South America don't wear much clothing) - but as populations migrated North into Europe and Asia, we simply couldn't evolve fast enough to get our fur back - so given that we are smart, dexterous, tool-using hunters, we took to wearing animal skins (ie clothes) instead. At that point, we didn't need to evolve hair - so we didn't do so. Clothing is a much better option for a species with that kind of life-style because you can dump them when you need to run fast - and in summer - and pile it on for slower movement in winter. Discovering fire is all well and good - but when it's ten below freezing and you are sneaking around stalking an animal, it's just not all that practical to carry a bonfire with you! SteveBaker 17:25, 9 March 2007 (UTC)[reply]

Concerning hair-loss, to argue that a warmer climate leads to hair loss is un-parsimonious, since almost all mammals living in warm environments have hair (elephants, humans, and naked mole rats being exceptions). I'd take a more complex approach, and argue parasitism, climate, and "cultural habits" all played a role in hairless humans. Remember also, that hair can protect from extreme heat and sun. Check out this article. --Cody.Pope 18:44, 9 March 2007 (UTC)[reply]

well to me #2 doesnt make that much sense by saying that human penises are that big, comparatively asians can be much smaller in comparrison to a lowland gorilla —The preceding unsigned comment was added by Maxx4444177 (talk • contribs) 18:41, 9 March 2007 (UTC).[reply]

Wrong, the average gorilla penis size when erect is on the order of 1.5in. Only humans with actual genetic disorders have penises that small. --Cody.Pope 18:47, 9 March 2007 (UTC)[reply]

The averages between races are only about 2 cm apart, if I remember correctly. The article would be race and penis size I think. [Mαc Δαvιs] (How's my driving?) ❖ 23:30, 9 March 2007 (UTC)[reply]

Could the loss of hair be due to sexual selection too, since as far as I can tell most women wouldn't like men who have lots of hair, and if this was true in the past too, people would have evolved to have less hair, and since we didn't need it there wasn't any reason not to lose it :) HS7 19:49, 9 March 2007 (UTC)[reply]

The hugely popular and highly regarded book The Naked Ape addresses your first and second questions. Grab it at your local library. -Arch dude 03:52, 10 March 2007 (UTC)[reply]

Binaural Beat Brainwaves?

I need some information on the long term effects of Binaural Beat Brainwaves.

Can these affect the brain in a negative way ?

Doubtful, but I do not know. Try the Wikipedia article on binaural beats; a search on Google Scholar will give you more detailed information. Just notice that while they stimulate neurons in an interesting way, any possible long or short-term effects aren't nearly as certain as the people who sell binaural CDs/software make them out to be. -- Consumed Crustacean (talk) 18:52, 9 March 2007 (UTC)[reply]

wave equations that represent atomic orbitals

we just had a test on atomic structure and chemical bonding.there was this one question which i dont think anyone was able to answer.there was a weird equation of the form psi=f(r,a0) and we were asked which orbital it represented 2s 2p 1s or 3d. i had no clue though i thought obviously it had something to do with schrodinger's wave equation because of the psi symbolcan anyone explain the question and solution.59.183.34.200 18:34, 9 March 2007 (UTC)[reply]

the wave equation may have something to do with the frequency of variation in the path of an electron in the orbital shells. as for the rest of it well, i'm only 15 and i have no idea.

-maxx- Maxx4444177 18:44, 9 March 2007 (UTC)[reply]

Was the question about a hydrogen atom, or a hydrogen-like atom? These can both be represented by the Schrödinger equation with a suitable potential, which can be solved analytically to give solutions of the form

\psi _{nlm}=R_{nl}(r)\,Y_{lm}(\theta ,\phi )

. The details of this are on the hydrogen-like atom page. If the equation you were given only depends on r (I assume a0 is the bohr radius, so constant for a given atom) then l and m must both be 0, as only

Y_{00}=constant

(ie, not a function). So as l is the angular momentum quantum number, l = 0 corresponds to an s shell. To determine the principal quantum number, n, you'll have to look at the exact form of the equation your given and compare it with the solutions given on the hydrogen-like atom page. The main bit to match it to will probably be the generalized Laguerre polynomials. Once you have n, this is the orbital number.Centie 23:39, 9 March 2007 (UTC)[reply]

You can tell the principle and azimuthal quantum numbers by looking at the wavefunction. For simplicity, say it is of the form

\psi =f(r)\,g(\theta )\,h(\phi )

, i.e. can be separated into a product of a function of the radial coordinate, and functions of the angular coordinates. The azimuthal quantum number is the number of angular nodes, i.e. how many zeros there are in

g(\theta )

for

0\leq \theta <2\pi

, plus how many zeros there are in

h(\phi )

for

0<\phi <\pi

. The number of radial nodes is how many zeros there are in

f(r)

for

r>0

. The principle quantum number is (the number of angular nodes) + (the number of radial nodes) + 1. --Spoon! 01:35, 10 March 2007 (UTC)[reply]

Superconducting Magnetic Levitation Materials

Does anyone know the specifications for the materials in this video, and where I would be able to buy those materials? Thanks. --JianLi 19:41, 9 March 2007 (UTC)[reply]

Oh jeez. Do some google searching until you find recipes for them, since you would have to make your own, I'm pretty sure. I don't know how sculpting a normal one would be into a train shape. It involves a ceramic composition of Ytterbium and some other things, which has to be cooled by liquid nitrogen and suspended in the air by the meissner effect. You'll also need resin, a fume hood, and a really hot scientific oven. Or you could buy a 40 dollar kit on WONDERMAGNET (reputable). [Mαc Δαvιs] (How's my driving?) ❖ 23:26, 9 March 2007 (UTC)[reply]

Sycosis

So. Global warming, are we causing it or not? The idea seems to be that there is a lot of evidence that global temperature changes are caused by changes in the amount of cloud and the temperature of the sun, and is on a 1200 year cycle. They say the modern fear of global warming was created by Margaret Thatcher to persuade us more nuclear power plants were a good idea, and that last time the temperature rose as much as it is now nothing to bad happened. And also that scientists get paid more if they predict something dramatic. But a lot of people say we are causing global warming, and if there really was all this evidence surely at least some of them might realise it isn't anything to do with us. But they haven't. So is this really true, or are we destroying the planet? And how much help will slightly cutting CO2 release be? HS7 20:28, 9 March 2007 (UTC)[reply]

The reference desk is not for rehashing debates on controversial subjects. You might want to read some encyclopedia articles on global warming if you want to learn more. Friday (talk) 22:39, 9 March 2007 (UTC)[reply]

Check out Carbon Cycle. Think of all the animal/plant life and take into account the amount being released by all naturally occurring sources on the planet. When carbon is liberated from stored sources, like wood (i.e. a forest fire) about 100-200 years of trapped carbon is released. Decomposition also liberates carbon trapped over about 100 years. Other large releases of carbon occur sometimes on mass by the ocean or by volcanoes (though this happens rarely). Now consider human actions. By burning fossil fuels we're releasing trapped carbon that was slowly "captured" over millions of years in a few decades. While there are some uncertainties concerning global warming, our actions can have unpredictable consequences, since nothing like this has ever occurred on the planet while we were around. Since these consequences could have devastating effects on the world economy and thus western quality of life, doesn't it make sense to err on the side of caution? Small changes that could be some what costly now, may prevent a world-wide depression. The only viable arguments against curbing emissions are generally economic, but when you consider large scale industrial saves by things as simple as changing the start of daylight savings time, these arguments seem tenuous at best. --Cody.Pope 22:45, 9 March 2007 (UTC)[reply]

You sound like you are already against the "skeptical view." I probably shouldn't get started on it. You can read some of the past discussions on it (three or four). Off the top of my head September 23, 2006 was the first one. Then the next one was in October. [Mαc Δαvιs] (How's my driving?) ❖ 23:22, 9 March 2007 (UTC)[reply]

"The idea", "they say" — you helpfully don't attribute your points of view, likely on purpose. The unstated "they" in these cases are people who are viewed as rather fringe in the scientific community. "A lot of people" are most scientists. But heck, if you've already made up your mind, why even ask? --24.147.86.187 00:16, 10 March 2007 (UTC)[reply]

function generator project

how to design the function generator of about 1MHz frequency and arbitrary waves like triangular,square and sine funtion —The preceding unsigned comment was added by Fayyaz1606 (talk • contribs) 21:40, 9 March 2007 (UTC).[reply]

Try this link for a low cost function generator design. --hydnjo talk 21:55, 9 March 2007 (UTC)[reply]

Emission Spectra

I have an idea about loop quantum gravity, but I need to know some information to develop it into a theory. What is the emission spectrum of a free electron? Also, it would help if you could tell me the best estimate of how many electron masses equal one Plank mass. Thanks, Max. *Max* 23:28, 9 March 2007 (UTC)[reply]

Google says ... Nimur 00:06, 10 March 2007 (UTC)[reply]

I tried that, but I wondered if I could get a better estimate. 65.93.208.26 03:32, 10 March 2007 (UTC)[reply]

I'm not a particle physicist, but I don't know if it's appropriate to talk about emission spectra of single free particles. Most of the quantum interactions that produce photons involve multi-particle or multi-state systems. Spectral lines in atomic emission spectra, in particular, are the result of excited electrons falling from a higher energy state to a lower one, producing a photon. The energy (and therefore wavelength) of the released photon is usually equal (or close to) to the amount of energy lost by the electron in its downward transition. So again, I don't think it's correct to think of a single particle as having any characteristic electromagnetic emission spectrum. I could be wrong though, I know little QED and my QM is rough. -- mattb @ 2007-03-10T00:18Z

Note: If the energy levels depend on the electron's velocity relative to the observer, assume that the electron is at rest before it emits the photon. Thanks. 65.93.208.26 03:32, 10 March 2007 (UTC)[reply]

Orders of magnitude (mass) says that the electron mass is 9.1×10⁻³¹ kg and the Planck mass is 2.2×10⁻⁸ kg. Ther fore, Planck mass is about 4×10²² electron masses. A Plank mass is about the mass of seven grains of sand. -Arch dude 03:34, 10 March 2007 (UTC)[reply]

Free particles can possess any amount of energy and thus have a continuous emission spectrum. 75.138.84.159 05:15, 10 March 2007 (UTC)[reply]

March 10

new technology

dear sir,

  please tell me about new inventions & research works.

—The preceding unsigned comment was added by 202.88.252.28 (talk) 04:19, 10 March 2007 (UTC).[reply]

Dove behavioural experiment

I have once read about a behavioural conditioning experiment with doves. They were given food at random intervals. The doves thought they were rewarded for their behaviour and developed individual bizarre routines and movements in order to get the food. Does anybody have a reference about this experiment. Thanks, Cacycle

What happens to the old heart

After a heart transplant,What happens to the heart that was removed.In other words what happens to the old heart. —The preceding unsigned comment was added by 68.161.97.103 (talk) 05:03, 10 March 2007 (UTC).[reply]