Revision as of 02:16, 25 March 2006

Reference Desk

March 18

Turkey?

Is it true that turkies really have a special trippy amino acid that can put people to sleep? Do wild turkies use this as some sort of defense mechanism to parylize predatory animals?TurkayTurkey 00:09, 18 March 2006 (UTC)

This is a well-spread myth. See Tryptophan#Tryptophan and turkey. Melchoir 00:14, 18 March 2006 (UTC)

Yes. Tryptophan is an essential amino acid (i.e. if you go without it long enough you die) and it's in many different foods. Sometimes I think I can tell when I haven't had enough, and I feel better after eating a banana or some yogurt, but that's probably just a placebo effect. —Keenan Pepper 01:13, 18 March 2006 (UTC)

The acid brought by turkeys creates a hot state of dependance and you freeze without it (it's called cold turkey). --DLL 22:30, 19 March 2006 (UTC)

Hitler's Syndrome?

What's the technical name of this disease? --LHbyot 02:28, 18 March 2006 (UTC)

Is there even such a syndrome? I've never heard of it. ☢ Ҡi∊ff⌇↯ 10:34, 18 March 2006 (UTC)

Fascism? --Fastfission 18:37, 18 March 2006 (UTC)

That's more political than scientific. However, the Napoleon complex may be somehow related. -LambaJan 22:02, 18 March 2006 (UTC)

Hitler Has Only Got One Ball WAS 4.250 21:50, 19 March 2006 (UTC)

• I think what the questioner was asking was not,"Describe the Hitler Syndrome," but rather, "What (mental) illness possessed Hitler?" Good question. He certainly was a strange man and did strange things, to say the least. He was, or thought he was, and in this thought he was joined by many, that he was a Wagnerian Hero; he won the loyalty of large part of an entire generation of "good Germans." He was a madman: so what, specifically, was he mad about? or to put it in Americanese, the guy was nuts, but what kind of nuts? Was it some really wierd (or maybe garden-variety) schizophrenia? If so, what kind? paranoid? Alas, Mr. Hitler never had the opportunity to be examined by a psychiatrist, or even a psychoanalyst. Too bad, since much of that discipline originated in Germany. Of course, it was regarded by Der Führer as Jewish trash. --Halcatalyst 04:26, 20 March 2006 (UTC)

Was he mad, or just an ambitious asshole? We may never know. Superm401 - Talk 21:22, 21 March 2006 (UTC)

• You might also say the gentleman was a megalomaniac, for which the formal name is the rather common Narcissistic personality disorder. --Halcatalyst 04:30, 20 March 2006 (UTC)

The State of Bubbles

Is a bubble a solid, a liquid or a gas? It has a definite shape (but whether it has definite volume, I'm not so sure of), it has a "shell" of liquid, and it contains air! One science student in this world (me!) is miffed and mystified by this seemingly simple question... --70.237.200.25 01:26, 18 March 2006 (UTC)

Bubbles are gaseous. Brian G. Crawford 03:19, 18 March 2006 (UTC)

The inside of a single bubble is a gas, but the really interesting case is when you get a bunch of bubbles together; the result is a foam that's somewhere between solid and liquid. Even in the case of a two-dimensional layer, you get interesting behavior:

• Deformation and Flow of a Two-Dimensional Foam Under Continuous Shear
• Hysteresis and avalanches in two-dimensional foam rheology simulations

Understanding these structures is important in industry, and as you can see, research continues to this day! Melchoir 03:35, 18 March 2006 (UTC)

Also see Antibubble, a drop of liquid separated from another liquid by a hollow sphere of gas. —Keenan Pepper 03:55, 18 March 2006 (UTC)

Whoa, that's just crazy! Melchoir 04:33, 18 March 2006 (UTC)

They're not that hard to make either. You just need a straw and some soapy water. —Keenan Pepper 05:13, 18 March 2006 (UTC)

Or a light n'frothy German beer, where they were discovered. -- User:Mac_Davis

As for volume, I got this from sphere:

The surface area of a sphere of radius r is:

${\displaystyle A=4\pi r^{2}\,}$

and its enclosed volume is:

${\displaystyle V={\frac {4\pi r^{3}}{3}}}$

So, there isn't a definite volume, but there is a definite relationship between your bubble's radius, surface area and volume, assuming it's spherical. If it's a semi-sphere you would need to halve the outcome of the formula. -LambaJan 21:54, 18 March 2006 (UTC)

On the usual size scale for bubbles, you have a hierarchy of forces, air pressure > surface tension > wind shear. So a given bubble forms into a sphere with a definite volume, rigidly fixed by the number of gas molecules inside; even if its shape does vary, the volume doesn't. Of course, there are bubbles with different volumes, just as there are rocks of different sizes. Melchoir 22:07, 18 March 2006 (UTC)

Just going back to the original question. As Melchoir said, the inside is gaseous. But isn't it the case that the surface film is a liquid? Which leads me to ask, what do we mean when we say "bubble"? Is it the visible surface, or is it the invisible gaseous contents, or is it both? JackofOz 23:40, 18 March 2006 (UTC)

I'd say, when most people say bubble, they mean either 'those things that you blow out of a straw thingy that float' or a prefix for 'bath'. I don't think it goes much deeper than that. Black Carrot 00:00, 19 March 2006 (UTC)

When we call those soapy things "bubbles", we are referring to either the external liquid film, or the film plus the gaseous contents, but (I would suggest) never just the contents (except perhaps in particular scientific contexts). To say "bubbles are gaseous" does not tell the whole story. That would be true of bubbles of gas rising through a liquid, but the questioner referred to a "shell of liquid", so they have the soapy version in mind. I believe a soap bubble cannot be characterised as one thing or the other. Part of it is liquid, and part of it is gaseous. JackofOz 05:59, 19 March 2006 (UTC)

Wow, thanks everyone for trying to help me solve this! I have a bit to contribute to this:

• a solid is technically defined as matter with a definite shape and volume,
• a liquid only has definite volume . . .
• a gas has neither volume nor shape (since it would exoand indefinitely without boundaries to hold it in)

But, this still raises an interesting question: Would bubbles be sonsidered as having a definite shape? They could be thought of as an amorphous solid, or a slow-moving liquid, I suppose, but I'm not sure;) all in all, I think we're back where we started again! 70.230.149.224 22:06, 19 March 2006 (UTC)

Oops, I wasn't logged in when I posted that ^ Joyskii 22:07, 19 March 2006 (UTC)

And I seem to need typing classes, because I have more typos than the rest of you all combined;) Joyskii

I fixed your formatting. How are we back where we started? Having conclusively determined that bubbles are made of up to three entirely seperate substances (even on the macroscopic level, except in the case of foam), the original question can be answered. As JackofOz said, one part of it is liquid, another part is gas. The bubble as a whole, being made of several entirely seperate pieces, would no more have a phase of its own than my entire glass of water has a phase of its own. The water has one, the glass has another, and the air above the water yet another. And no, bubbles don't have a definite shape, but that's not the only criterion. Black Carrot 02:03, 20 March 2006 (UTC)

Fuel Oil

Does improper burning of fuel oil in an oil furnace produce carbon monoxide or carbon monoxide? (Vern)

Yes. Also CO2, NOx, H2O, and hydrocarbons of various lengths. Carbon monoxide is the result of incomplete combustion.

--Nagle 04:57, 18 March 2006 (UTC)

Magnesium & sodium hydrogensulphate

I am in the process of completing a SATs mock exam for my science homework.

Can you please help with the following question:

Magnesium is added to a solution of sodium hydrogensulphate. What would you expect to see forming on the magnesium? —This unsigned comment was added by LGardiner (talk • contribs) .

White stuff-- Magnesium sulfate. 1590 —This unsigned comment was added by Alteripse (talk • contribs) .

Precipitation of an insoluble salt and the formation of a gas are both driving forces in this reaction. Hydrogen sulfate ion is a strong enough acid to oxidize magnesium. —Keenan Pepper 17:10, 18 March 2006 (UTC)

No. Magnesium sulphate is reasonably soluble. The question is obviously leading to what is observed on the surface of the magnesium, and that is bubbles of hydrogen gas. The strip of metal would dissolve, leaving a colourless solution - technically a mixture of magnesium sulphate and sodium sulphate.G N Frykman 09:49, 19 March 2006 (UTC)

Hmm, must have remembered wrong. The sulfates get less soluble going down the group, which is the opposite of the hydroxides. —Keenan Pepper 19:08, 19 March 2006 (UTC)

Microchips

Does a microchip have a magnet in it? Can a microchip have a magnet in it?

Yes, the ferrite rod is an essential component. See microchip. --Shantavira 14:22, 18 March 2006 (UTC)

For microchip implants, yes, the ferrite rod wrapped in copper wire acts as a radio antenna to send a signal to the scanner. Generally, ICs don't. — TheKMan 23:40, 18 March 2006 (UTC)

Dietary Advice

How healthy is a cup of minestrone soup from a packet? How would this compare with an equiavlent volume from a can? I like minestrone... --Username132 (talk) 18:29, 18 March 2006 (UTC)

To give a good answer I would need to know specifically which products you're talking about. If high temperatures are used in dehydrating the food, this can cause the breakdown of some vitamines and proteins. However, the matter of ingredients is more important. What is the quality of the vegetables? probably not very high if they need to add natural/artificial flavors. Your best bet at a healthy product is to buy good organic vegetables, use filtered water, and make enough to store for your convenience. -LambaJan 21:43, 18 March 2006 (UTC)

It depends on the comparative ingredients of the two soups (and nothing else, though the flavour might vary). If the products have nutritional labels, they will tell you more than we can. Notinasnaid 21:42, 18 March 2006 (UTC)

Does it really matter if a protein has been denatured before I eat it? I mean, digestive processes are gonna do that anyway?

Right. doesn't matter. When you fry an egg, you denature all the proteins. That is , the 3d structure of the proteins are mangled due to the heat. THat's why the egg whites turn cloudy. But the chain of amino acids is intact. The chain of a.a. s is taken apart in digestion, so you end up with a soup of amino acid molecules, that get's absorbed into the blood. When you cook meat, say, you denature meat proteins, but more importantly, you denature the proteins of bacterial and parasites, ie kill them. GangofOne 08:02, 19 March 2006 (UTC)

Nothing is "healthy", or "unhealthy," its how much you eat of certain things that can be unhealthy or healthy for different people. -- Mac Davis] ⌇☢ ญƛ. 01:30, 19 March 2006 (UTC)

Intravenous Medicine Bottle Membranes

What are those membranes covering the tops of bottled of medicine destined for injection made of? --User:58.65.136.146 19:34, 18 March 2006 (UTC)

Rubber. --BluePlatypus 20:49, 18 March 2006 (UTC)

Yeah, probably silicone rubber. Brian G. Crawford 21:37, 18 March 2006 (UTC)

How does it seal itself back up? User:58.65.136.146 00:10, 19 March 2006 (UTC)

Through the ordinary elastic properties of rubber. I don't think the bottles are meant to be stored for long after having been punctured though. I don't have any experience with IV bottles, but I've sealed GC vials which have the same kind of top (rubber disc and metal collar which you clamp on), and the rubber disc is a bit thicker than one might think, about 2-3 mm (1/8 inch). --BluePlatypus 01:41, 19 March 2006 (UTC)

Latin name for new species

I've also posed this question at the language reference desk: I'm writing a chapter that features microscopic machines, like the nano assemblers spoken about by Eric Drexler et al, and would like it if I could use a Latin species name to refer to them.

A strange question, I know, but if anyone out there thinks it might be fun to come up with a few suggestions, I'd be most appreciative.

Adambrowne666 23:26, 18 March 2006 (UTC)

The short answer is no, it are not biological species. KimvdLinde 01:07, 19 March 2006 (UTC)

I haven't made myself clear. I'm asking people to pretend they've discovered a microbial species which happens to be mechanical. What would it be called?Adambrowne666 06:27, 19 March 2006 (UTC)

Microsoftium xbox3600000ium GangofOne 08:04, 19 March 2006 (UTC)

Machina automatos sapiens ☢ Ҡi∊ff⌇↯ 14:59, 19 March 2006 (UTC)

Nice try but you mixed latin and greek and got all the endings disagreeing. alteripse 02:02, 20 March 2006 (UTC)

So what, do you have any idea how many species names are simply "latinized" hell, people latinize their own names sometimes :)--152.163.100.74 03:04, 20 March 2006 (UTC)

Be specific! back to see WP:RD/L. --DLL 22:25, 19 March 2006 (UTC)

To be more specific, the nanomachines are the traditional assembler type, but in a 17th century context (it's a long story) - in the novel, they're described as "Mechanical spiderlets so surpassing small that anything tinier could scarcely be imagined. Their enginery is wrought of microbes’ whiskers, and moves by wheels and spiral pulleys, as doth a clock." Hope this helps. Adambrowne666 07:04, 21 March 2006 (UTC)

Nanomycoplasma ubique WAS 4.250 11:23, 23 March 2006 (UTC)

How much power is used in the US/World

For a paper I'm writing I need to know how much energy is used (in watts or BTUs) in the world or US, thanks. --orphan frequently 23:28, 18 March 2006 (UTC)

• From the CIA factbook, the world produced 15.85 trillion kWh and consumed 14.28 trillion kWh in 2003. I have no idea whom the world is exporting electricity to, although the CIA factbook says we "exported" 536 billion kWh of it. :) --inks 23:40, 18 March 2006 (UTC)

Thanks, and in case anybody's wondering, if everyone in the Us cooked their hot dogs with a parabolic reflector instead of a microwave, we would save approximately .005% of the world's power.

That much? How many hot dogs are we cooking? Melchoir 04:44, 19 March 2006 (UTC)

Show us your calculation. GangofOne 08:01, 20 March 2006 (UTC)

That sounds dandy and all but what happens when I need my late night hot dog fix? It would be interesting to look at the fraction of foods requiring only minimal heat for preparation (like canned soups, or s'mores) and then figuring the timeslice of a day that they could reliably be prepared in, as a way to estimate potential savings from 'free-energy' like solar ovens. I predict it would be unparalleled by the amount of energy you would expend convincing everyone that it was a good idea to cook things in a big foil-covered contraption.

When energy prices get so high noone can afford it, it won't take any to convince people to use free alternatives. (Ie, a free market argument.) However, I suggest looking at bigger picture. Your TOTAL household energy use, and ways it can be economized, and total energy use in society. It doesn't take much to see problems in the future. Shortfalls, rapid price rises, economic dislocations. According to what I read, rational creatures can use their rationality to plan ahead and avoid some unnecessary grief; but it's not clear that's true, based on what I see. GangofOne 20:29, 20 March 2006 (UTC)

Here is the almost perfect graph for you Herzog, I forgot where I got it, but it was either wikipedia or the US Department of Energy. -- Mac Davis] ⌇☢ ญƛ. 05:11, 21 March 2006 (UTC)

March 19

Uneven Bandwidth Sharing Network

I think my housemate has found a way to siphon off all the internet bandwidth for himself. Is this possible? --Username132 (talk) 00:12, 19 March 2006 (UTC)

It depends on what kind of networking equipment you share. If it's something pretty fancy (such as a Cisco router, or a Linux box) it may feature traffic shaping, which lets the person who configured it do all kinds of stuff. If, however, its an off-the-shelf little ADSL gateway (linksys, belkin, netgear) then that feature isn't present (at least not in the UI). He's maybe just running lots of P2P apps flat out. -- Finlay McWalter | Talk 01:10, 19 March 2006 (UTC)

Agreed. He might think he's just downloading one song, but he'll be uploading as well.--inks 02:32, 19 March 2006 (UTC)

P2P apps tend to use lots of connections and can therefore take bandwidth far more aggresively than the single TCP stream of a simple http or ftp download. IP doesn't really enforce fairness, its more a who pushes hardest wins type environment (ofc if you design protocols that push things too hard you'll just end up with loads of packet drops and noone will get good results, see ddos attack for an example of this situation). Plugwash 02:47, 19 March 2006 (UTC)

With regards to traffic shaping, you can probably add that feature to your ADSL gateway if you are prepared to install OpenWRT. It's free, but installing and configuring it to your needs is a geek-only task. --Robert Merkel 03:18, 19 March 2006 (UTC)

Steel Wool

Could somebody please tell me the typical percentage compositions of the substances that make up standard steel wool? Thankyou Vollsa 06:14, 19 March 2006 (UTC)

The article steel wool seems to suggest that it's 100% steel. Unless you're counting soap, I guess; is that your question? Or are you asking about the elemental composition of the specific variety of steel? Melchoir 06:21, 19 March 2006 (UTC)

I very much doubt that steel wool material is tightly controlled; it would probably vary from batch to batch of raw material depending on what iron ore was used etc., but generally, steel wool is made of steel so one would expect certainly iron (probably 98-99%), carbon and oxygen, and possibly some trace sulfur and nitrogen. No way to know exact percentages without contacting a specific manufacturer --Fuhghettaboutit 07:31, 19 March 2006 (UTC)

...and asking them very nicely to run a sample of their product through a mass spectrometer. --inks 09:22, 19 March 2006 (UTC)

Neutralization

Dear users,

Can anyone explain to me what is actually happening microscropically when a Antacid Tablet is inserted into Hydrochloric Acid? I need to write a hypothesis for this experiment (analysing and comparing the neutralizing capabilities of commercial antacids) and i need some very detailed explanation. Thanks!

p.s.: I am in the 9th grade so please don't include that much mathematics! Thanks!

The basic replacement reaction is:

   Acid + Base -> Salt + Water

Note that "salt" doesn't mean just table salt, for example:

    HCl  + CaOH -> CaCl + H20

StuRat 14:18, 19 March 2006 (UTC)

I'm afraid the above equation is wrong. It should read: 2HCl + Ca(OH)2 --> CaCl2 + 2H2O. But that is not the point. Commercial antacid tablets do not consist of bases as such, because they would be harmful to the stomach. They are much more likely to be made from sodium hydrogencarbonate, and the general equation is: acid + hydrogencarbonate --> salt + carbon dioxide + water. Thus: HCl + NaHCO3 --> NaCl + CO2 + H2O. The project thus boils down to an investigation of how much HCl (of known and equal concentration every time) reacts exactly with a known mass of antacid tablet. You could look up titration, but an easier way, if you had large numbers of each make of tablet, would be to take a fixed volume of acid each time, and see how many tablets you could add before the fizzing stops. The fewer the tablets, the more effective they are!G N Frykman 14:52, 19 March 2006 (UTC)

Sodium bicarbonate isn't a "base as such"? What does that mean? This bottle of Maalox contains aluminum hydroxide and magnesium hydroxide, and the latter is definitely a "base as such". —Keenan Pepper 18:52, 19 March 2006 (UTC)

• He is refering to the strength of the base. All of the first and second group metal hydroxides are classified as strong bases, meaning that they completely dissociate in water. For example: Ca(OH)2 is a compound of Calcium, from group 2 of the periodic table, with Hydroxide. When put into water, all of the molecules of Ca(OH)2 will go into solution. When you are dealing with weak bases like sodium bicarbonate/baking soda, only some of compound actually dissolves into solution. (If you want to get technical, this amount is defined by the acid/base dissociation constant. I don't know the number off-hand). If Maalox has Mg(OH)2 in it, then that is a strong base, though it probably does not have a lot it. Remember that a strong base doesn't always have to be corrosive and deadly. Hope this clears some things up. --Chris 22:15, 19 March 2006 (UTC)

There never were, or are, any "molecules" of calcium hydroxide, which is reasonably ionic in character, but not very soluble. I can't believe that people deliberately ingest aluminium hydroxide as an antacid without severe health risks. Of course aluminium hydroxide (very insoluble) and magnesium hydroxide (pretty insoluble) are both bases, as is sodium hydrogencarbonate (if we really want to get technical, of course, the hydrogencarbonate ion is amphoteric), because they are all proton acceptors. Strong bases are not necessarily corrosive, but strong alkalis definitely are, because they are very soluble. Sodium hydrogencarbonate solution has a pH of around 9 (depending on concentration, of course) and, when ingested into the stomach as an antacid, merely produxes salt water and a lot of burp-making carbon dioxide...G N Frykman 17:44, 20 March 2006 (UTC)

Airplane component question

On large passenger airliners, I have noticed that there are small rods, shaped a bit like small antennas, perhaps half a meter long, sticking out from the trailing edge of the flap tracks under the wings (like here). There seems to be one on each flap track, plus a few extra ones on the winglet (like in this picture). I know they're not antennas - what are they? — QuantumEleven | (talk) 13:06, 19 March 2006 (UTC)

Your "like here" site can't be viewed by people other than you. I would guess those instruments measure air speed. StuRat 14:14, 19 March 2006 (UTC)

I know the rods QuantumEleven is talking about, but I don't know what they are, either. If you can't view that picture (though it worked for me), here are three more: . The ones I've seen, and the ones in these pictures, are shorter, more like 20 cm than 50. I don't think they're pitot tubes (which are usually mounted forward on the fuselage, and which are the airspeed instruments I'm familiar with), but I suppose they could be related. Not all airplane wings have them; only some. —Steve Summit (talk) 16:42, 19 March 2006 (UTC)

Ah, yes, I see the problem - the site blocks direct access to the picture in question, you need to click through their menu to get to it: -> Walkarounds -> Airbus -> Airbus A330, then it's the middle picture, four rows up from the bottom.

They definitely can't be pitot tubes, because pitot tubes (as Steve Summit said correctly) have to be forward-facing. As for airspeed measurement, that's taken care by the pitot and static ports at the front of the fuselage, where the air flow is least disturbed (it's pretty messed up behind the wing!). I had thought that they might be some kind of ion discharger - they act to stream off excess charge from the airplane so it doesn't build up a strong charge (which might damage instruments if it comes into contact with another object), but that's just speculation. Anyone have any better explanations? Thanks in advance! — QuantumEleven | (talk) 18:14, 19 March 2006 (UTC)

Would a Boundary layer fence be installed on the trailing edge? EricR 18:55, 19 March 2006 (UTC)

No, they wouldn't have any effect there. A boundary layer fence exists to prevent flow parallel to the wing (ie outward), so by nature it has to stretch for most of the wing chord, and it doesn't look anything like the little rods. A good illustration of one is here (the airflow is coming from the left).

This is turning out to be quite a mystery! :) — QuantumEleven | (talk) 07:04, 20 March 2006 (UTC)

Wouldn't it simply make the aircraft more aerodynamic? Kilo-Lima| 18:28, 19 March 2006 (UTC)

Is it possible that they are some sort of antenna? --Anonymous, 23:55 UTC, March 19, 2006.

Not as far as I can tell (but, then, I could be wrong!). All the antennas are on the fuselage, in aerodynamically shaped fins. The end of a flap track seems a very daft place to put an antenna - why go to all the trouble to run wiring through the wing, and then through the flap track (which moves, making this a difficult task) if you can just stick it on the fuselage? But, then, again, I could be overlooking something... — QuantumEleven | (talk) 07:00, 20 March 2006 (UTC)

The are called static discharge wicks and are for discharging any charges that accumulate on the surface they are attached to. Obviously charges on the surfaces are not a good idea because an aircraft wing holds thousands of gallons of fuel. I have no idea exactly how they do their job but I was responsible for calculating their drag when I worked in Aerodynamics at British Aerospace. They are found on an Airbus wing on the flap track fairings (that hide the flap mechanisms), the flaps, the ailerons and the winglets - Adrian Pingstone 09:19, 20 March 2006 (UTC)

Presumably the wicks work by concentrating the static charge (incidentally, that article needs some work) at their tips, where the curvature is very large. Concentrated charge will be released into the air more quickly. --Tardis 18:55, 22 March 2006 (UTC)

Keratolysi exfoliativa

What is Keratolysi exfoliativa ? Is there any effective treatment for it ?

• That's Keratolysis exfoliativa, by the way. --jpgordon∇∆∇∆ 18:07, 19 March 2006 (UTC)

Destruction of skin cellules by defoliation is what's meant. The most efective cure for skin diseases is ... general good health. That state may be obtained when you think that your life is good. IANAP, so do consult a true physician. --DLL 22:20, 19 March 2006 (UTC)

nuclear threats

what are nuclear threats?;how seriuos are they;what would be its global out come;what will happen with our energy consuption

Are you talking about the use of nuclear weapons, dirty bombs, nuclear reactor accidents, intentional sabotage of nuclear reactors, nuclear waste disposal, depleted uranium pollution, side effects of nuclear medicine, radon gas, or what ? StuRat 17:21, 19 March 2006 (UTC)

If you are talking about the threat of nuclear warfare, then it depends on exactly what sort of scenario you are proposing (i.e. a terrorist with one crude bomb or a massively nuclear state like Russia launching a full attack), and even then will be debateable. If you are talking about nuclear reactors, the global and local threats of major accidents is very low. --Fastfission 21:37, 19 March 2006 (UTC)

Make that a low chance of things going wrong but a high risk in terms of potential results. Multiply a low chance with a high risk and both rather vague and the outcome is way too vague to conclude anything. But the waste takes a very long time to 'neutralise' (thousands of years, although that depends on what you call safe) and there's no telling what may happen to it or the place it's stored in in the meantime, and this uncertainty should be added. So the biggest problem is the impossibility to assess the risks involved. DirkvdM 15:15, 20 March 2006 (UTC)

Question; Shadow, reflection or ?.

This shadow? is visible on the left and right sides of a moving vehicle during times of no direct sunshine. ie; before sunrise, after sunset or during overcast conditions. The shadow is less distinct than that seen directly under the vehicle, and is not seen when the vehicle comes to a stop. The shadow appears to be in the shape of a truncated half-elipse. They are most easily observed when following a large truck but once a person knows what to look for, they can be seen beside any moving vehicle during times of indirect natural light. What are they? Thank you. -----

(removed leading spaces to fix formatting) --LarryMac 15:43, 19 March 2006 (UTC)

Essentially there are an infinite number of shadows under diffuse lighting, one from every particle in the sky which is reflecting sunlight down to the truck. The shadows reach the highest density under the truck, where it is darkest, and then the next most heavy density would be at the sides of the truck in the middle. You can see this for yourself if you shine multiple different colored lights at an object from different positions above the object. You will see many shadows, each a different color, but they will all come together underneath the object. StuRat 17:13, 19 March 2006 (UTC)

physical science

is it possible for south africans to uterlise free on-line turts for physics .please if the is may i get the web address for it

Free online turtles ? StuRat 17:48, 19 March 2006 (UTC)

Open Source turds on the Internet? DirkvdM 15:17, 20 March 2006 (UTC)

Take a look at learn.co.za. Superm401 - Talk 22:00, 19 March 2006 (UTC)

http://www.lightandmatter.com/ free introductory physics and astronomy textbooks, available to everyone in South Africa or anywhere else in the universe that is internet-connected. For a list of books to search through with more books at all levels in English, visit the all-time great website http://onlinebooks.library.upenn.edu/ 25,000 books listed, all free, with new ones everyday. GangofOne 08:20, 20 March 2006 (UTC)

Free High School Science Texts is written by South Africans for South African senior secondary students, and released under the GNU FDL. Anon 03:01, 24 March 2006 (UTC)

The feeling of being watched

Is the "feeling of being watched" alluded to so often in fiction only a myth, or is there any physical justification for it? Thanks.Loom91 15:20, 19 March 2006 (UTC)

• There are different ways you could take this. I'm assuming you mean something other than just being aware, perhaps subconsciously, of things around you which would give you clues as to whether you were being watched, but mean more specifically whether or not humans can tell, without other evidence, that people are looking at them. I'm pretty sure the answer is "no" on that last part, though I remember reading about some crackpot who had tried to prove that people had some sort of psychic intuition (the same guy also worked to prove that dogs were psychic, I believe). --Fastfission 21:34, 19 March 2006 (UTC)

• I find that when I'm looking down at something in a room full of a decent amount of people, and I look up, I always happen to look at the person who is looking at me. Maybe it's just because I notice it more often then not. I'm not sure if there is any explaination behind it. Just like how a room always tends to get silent at 20 after or 20 to. --Chris 21:53, 19 March 2006 (UTC)

That kind of sixth sense must be real as it is experienced by various people and depicted by every fiction authors. Ancestral survival knowledge that, when in a place you do not know, intending to do certain things, you must be in alert. Then, when once you find that you are really watched, it may be mere coincidence but you were prepared to it. --DLL 22:14, 19 March 2006 (UTC)

The person you're thinking of is Dr. Rupert Sheldrake. The competing ideas are that a)people notice things they don't realize they notice and b)people's eyes are drawn to someone's moving head as they turn around vs c)people are psychic. I'm replicating his experiment for Science Fair, and if nobody objects to me spreading a little original research, I'd be glad to share the results when I have them. BTW, do you know of any name for this, phrase that describes it, something in a book perhaps? Nobody seems able to come up with a good word for it. "Feeling of being watched" seems a bit long.

Not really, DLL, it's quite possible for most people to believe something that has no basis in fact whatsoever. *cough*flat earth*cough* Black Carrot 22:23, 19 March 2006 (UTC)

see Sheldrake's books, "Seven Experiments That Could Change the World" (1994) and "The Sense Of Being Stared At" (2003) GangofOne 00:25, 20 March 2006 (UTC)

Not quite being watched, but when you "feel a presence", I think it's because of low-frequency noises coming from the person. I paid attention to it and realized it's something in the hearing sense, but you can't quite put a finger at it. Eventually, after some thought on this, I did an experiment with low frequencies and found out the result is exactly the same. My guess is that it has something to do with these factos:

1. You can't tell where bass sound is coming from
2. If you hear such a sound but you can't associate it visually with anything, your brain assumes it comes from behind you.
3. If you just stand somewhere you will produce such noises.

Now what else is involved, I dunno, and I never really bothered to do further experiments. But an interesting thing is that years later I saw a documentary on Discovery Channel where they used low frequency noises to stimulate "hauntings". People felt a presence and felt like being watched.

So my guess is, I was right. \☺/ ☢ Ҡi∊ff⌇↯ 00:53, 20 March 2006 (UTC)

Awesome. But what if there's another sense (a genuine "someone's here" sense) and you just tend to mistake the one for the other without any training? Black Carrot 01:46, 20 March 2006 (UTC)

I've read somewhere about an experiment similar to Kieff's. Several people said that a room was haunted, and it turned out that the reason was a table fan, which made a 15 Hz sound (too low to be audible by human ears). /130.238.41.144 13:54, 20 March 2006 (UTC)

explanation for the seasons of the earth

If a rocket is captured into orbit by a planet, it will always point the same face to the body it circles. Yet the earth does not do the same thing with the sun. Instead, it points its North-South axis in the same direction at all times (ignoring effects like the rotation of the galaxy). If it were like a rocket ship, and pointed the same face to the sun at all times, it would not have seasons. Why does the earth not follow the same principle as the rocket? The Mad Echidna 17:13, 19 March 2006 (UTC)

The only reason a rocket always has one part facing a planet is that they choose not to spin it. In the case of planets and moons, they all initially have a spin that keeps them from having the same face toward the object they are orbiting. However, if the planet or moon is relatively close to the body it is orbiting, then tidal locking will eventually cause it's spin to change, typically so that one side always faces the body it is orbiting. This has happened to our Moon, for example. StuRat 17:41, 19 March 2006 (UTC)

If one side of the earth always faced the sun there would be no day or night but we would still have seasons. They would be extra-crispy and super-crispy instead of summer and winter. EricR 22:04, 19 March 2006 (UTC)

No they wouldn't. Seasons are caused mainly by days being of different lengths at different times of year. Were the same face of the earth to remain towards the sun at all times, we would have neither days nor seasons, other than a minor variation due to the earth's slightly elliptic orbit. Black Carrot 22:12, 19 March 2006 (UTC)

See the seasons article. The irradiance of a give area of the earth's surface changes as the angle of incidence of the radiant flux from the sun changes throughout the year. EricR 23:55, 19 March 2006 (UTC)

The false claim "if a rocket is captured into orbit by a planet, it will always point the same face to the body it circles" is the source of the OP's confusion. Rockets are not special: they obey the law of conservation of angular momentum just like any other object. Artificial satellites that need to face the Earth at all times must be carefully spun so that their period of rotation matches their period of revolution, and this synchronization maintained by use of attitude controls. Gdr 23:58, 19 March 2006 (UTC)

Right, I'd neglected the angle of incidence, but that doesn't change that there would be no seasons. Even factoring that in, all it means is that different parts of the globe would be different temperatures, not that any part of the globe would experience temperature change, since it would still face the same side towards the sun at all times. Black Carrot 01:41, 20 March 2006 (UTC)

Since the earth's axis is tilted the latitude at which the solar radiation is normal to the surface changes as the earth revolves about the sun. During the equinox the sun's rays are normal to the surface at the equator, during the solstices at the Tropic of Capricorn or Tropic of Cancer. EricR 02:50, 20 March 2006 (UTC)

"If one side of the earth always faced the sun," one side of earth would always face the sun. You're talking about the side of the earth facing the sun changing. Black Carrot 20:14, 20 March 2006 (UTC)

I think i see the problem, take a quick look at the image on the bottom of the Axial tilt page. The direction in which the axis of rotation of the earth points remains constant (ignoring precession) during the year. The earth would still be rotating in order to keep one side always facing the sun. The direction the axis points would not change because of the conservation of angular momentum.

Imagine you are standing on the Tropic of Cancer during the summer solstice, halfway around the "dayside" of the planet. The sun is directly overhead, 90° above the horizon. As the year progresses, your side of the planet always faces the sun--but the sun begins to drop towards the horizon. Half a year later during the winter solstice the earth has revovled 180° about the sun, and rotated 180° about its axis. But the direction the axis points has remained the same and you see the sun 23.45° above the horizon. EricR 00:47, 21 March 2006 (UTC)

I see. I hadn't considered the axis of rotation not being able to be vertical in this hypothetical universe. I'd assumed that "the same face to the sun at all times" meant "the same face to the sun at all times", and reasoned from there. Were the axis to remain the same as it is now, yes, there would be seasons to some extent. Except in that broad circle on the back of the planet where there'd never be any light at all. Good call. Black Carrot 01:39, 22 March 2006 (UTC)

Electric current

Why is it that an electric current is generated when a coil is rotated between the magnetic flux that is what happens at the atomic level that leads to the flow of electrons in a mattel conductor? —This unsigned comment was added by Aggarwal kshitij (talk • contribs) .

Have you read the article Electromagnetic induction? —Keenan Pepper 18:42, 19 March 2006 (UTC)

dopamine antagonist's

I am doing some simple research on parkinson's drugs to compile data so the question is I realize mirapex is a dopamine antagonist but is requip and comtan also dopamineanergict

Umm... see Requip and Comtan? —Keenan Pepper 21:23, 19 March 2006 (UTC)

By the way, you're probably thinking of dopamine agonists, not antagonists. --Uthbrian (talk) 02:17, 20 March 2006 (UTC)

Light travel from the early Universe to Earth

Earth is receiving light from the early Universe from over 13 billion years in the past.

1. Why didn't that light overtake the matter which is now earth in the first billion years?

2. Did the early inflationary period prevent this?

3. If so, how?

In my simplistic view, light from the early Universe must be vanishing as an ever expanding event horizon that passes Earth in all directions.

4. Will the curvature of spacetime prevent the early Universe from vanishing faster than the rest of the Universe for future observers?

--jwalling 19:38, 19 March 2006 (UTC)

• The furthest stars from us are moving away from earth at a rate approaching the speed of light, and proportional to the distance between us. See hubble constant. Light does not vanish, it diminishes in intensity by the inverse of the square of distance.--inks 21:25, 19 March 2006 (UTC)
  • In the early Universe, the average distance between all matter was a small fraction of the average distance today. For 13 billion years the average distance had to increase faster than the speed of light to prevent ALL the ancient light of the early Universe from reaching EVERY physical object, including Earth or its matter constituents. If that ain't so, I need another explanation that fits the conjecture the early Universe will be visible everywhere for billions of years henceforth at diminishing energies. --jwalling 00:22, 20 March 2006 (UTC)
  • postscript: I was using the vernacular vanish to describe the effects of movement in relationship to an observation horizon. Objects far enough apart (Hubble distance) are receding at speeds greater than the speed of light. In theory you could physically travel away from a visible distant object to a place in space where light from that object would cease to reach you due to the expansion of the intervening space. That light source would vanish, so to speak. --jwalling 00:51, 20 March 2006 (UTC)
    • p.p.s.: To close this circle, does the light from the early Universe have an observation horizon? I don't think any of the responses so far have answered that question. --jwalling 01:10, 20 March 2006 (UTC)

We don't see light from our part of the universe when it was young — that light is long gone from around here, as you point out. We see light from other parts of the universe when they were young, light that has travelled 13 billion light years to get here. The expansion of the universe has created those 13 billion light years of space for it to cross. See our Big Bang article.

Cosmic inflation is a red herring here. The inflationary epoch was long over by the time the Cosmic Microwave Background began to shine. Gdr 23:44, 19 March 2006 (UTC)

Jwalling: Earth is receiving light from the early Universe from over 13 billion years in the past. Why didn't that light overtake the matter which is now earth in the first billion years?

This is an excellent question, which is rarely answered properly.

To rephrase, if the farthest quasars are about 13 billion light years away AND if the high redshifts indicate they're receding at nearly light velocity, how can both be true? If they're 13 billion light years away and receding at nearly light velocity, then 13 billion years ago they were much closer, therefore the light from them isn't 13 billion years old.

The confusion comes from imprecise use of the term "distance", mainly by the popular media, and poor explanations of the expanding universe. In cosmology there are several "distances":

Emission distance -- the distance the source was when the light we SEE NOW left the source (there and then).

The co-moving radial distance (or reception distance) -- this is the tape measure distance if we could somehow at this cosmic instant measure the distance to the object when the light we see arrived here. This is what is used in the Hubble Law.

When pondering distance, we tend to think of the above two. However there is another "distance" you see quoted in the popular print (because they think the above is too complicated to explain). It's the lookback time -- yes actually a time measuring how long the light we see NOW took to cross the EXPANDING universe and arrive on Earth. It is the light travel time in an expanding universe. This time is then multiplied by the speed of light and then quoted as the distance to the object (d = ct).

Yet the distance based on lookback time can be non-intuitive because of popular misconceptions about the expanding universe. Remember, the universe is NOT expanding from objects "flying outward" through fixed space like particles from an explosion. If that were so, light from ancient nearby objects would have long reached earth's vicinity -- relativity says you can't out run a photon, nor does a rapidly receding object slow down emitted light. Rather objects are receding because the fabric of space itself is expanding, increasing the distances between objects.

This "stretching" of space interposes additional distance during light's travel period. THIS explains why light emitted 13 billion years ago when a rapidly receding object was much closer takes 13 billion years to reach earth -- because the intervening spatial fabric expanded during the travel period, interposing additional travel time. Thus light from our relatively "local" early universe can still take many billions of years to reach us.

At close distances (i.e. small redshifts), the emission distance, co-moving radial distance, and lookback distance will all be the same. At large distances (i.e. large redshifts), these distances will diverge. E.g, consider an object with a lookback distance of 13.2 billion light years. The emission distance would be about 4 billion light years, but the co-moving radial distance about 28 billion light years.

This relatively simple concept is rarely explained clearly in most "Big Bang" articles. Joema 14:45, 20 March 2006 (UTC)

* Excellent response. Thank you for taking the time. --jwalling 02:04, 21 March 2006 (UTC)

p.s. Another misleading example of the vernacular is asking how old light is that reaches Earth. Since photons travel at the speed of light, photons don't age. Photons from the early Universe arrive after 13 billions years as “young” as the instant they departed ;-)

quantum mechanics and the occupation of matter in space

Do particles really jump in and out of existance? If they do, is it possible for one put ones hand through a wall without ones hand disturbing the matter that makes up the wall and vice versa? -Danke (trancemammal)

Particles cannot simply "jump in and out of existance", although they can exist without a definite location. If the wall is made of metal, for instance, then any particular electron in it is "smeared out" over a probability wave and has no definite location, but the total number of electrons is a conserved quantity and cannot change. You can't put your hand through the wall because the electrons repel the electrons on your hand, even if no single electron is definitely right there where you're touching it. —Keenan Pepper 21:08, 19 March 2006 (UTC)

Well, you can argue for virtual particles "jumping in and out of existence", though on the other hand you can reasonably call that a bookkeeping trick. Shimgray | talk | 21:48, 19 March 2006 (UTC)

Actually, they do jump in and out of existance, or the universe wouldn't work. Electric and inter-atomic and magnetic forces would all break... nothing would hold together. (We don't know yet on gravity, the fouth force. Stand by!) The book keeping refers to the probability theory some of the math used in the field of Quantum physics, but the specific field is Quantum electrodynamics. And according to current theorists, the particles are constantly coming into and out of existance in a complicated interchange governed by the Law of Conservation of energy. That's the 'bookkeeping' part– meaning debits and credits (of mass and energy) have to balance exactly, as in money matters (see: Double entry book keeping). Certain expermental results have indicated that in certain circumstances a particle or subatomic particle has to be two places at once, or the equivilent, they must each have a coresponding anti-particle, which may be expressed as a negative energy state. (bookkeeping again). The Electron's anti-particle is called the positron. Anti-matter refers to all the 'opposite' particles, as in Star Trek. Expermental data based on light wave behaviour gave strong evidence the quantum theory was indeed correct. Einstein never did accept quantum theory, saying that "God wouldn't play with dice" (or something similar). Another article on the topic would be unified field theory.

These matters primarily involve subatomic particles, so you'd have difficulty putting even a single atom through your wall, much less your whole hand. Check back in 872 years, and we'll give you an update! FrankB

Why 872? —Keenan Pepper 00:43, 20 March 2006 (UTC)

Video format change software

I want to change the video format 3GP File to anther kind of format of video? please I nead program to changes vidoe format.

Have you seen the 3GP page? EricR 21:08, 19 March 2006 (UTC)

I cannot find anything about nuclear sap

Hello! I am doing an assignment on nuclear sap, however, it seems there is no information regarding it. Will you please tell me what its functions are? Thank you for your time. -Sandy

Try searching for nucleoplasm. EricR 22:17, 19 March 2006 (UTC)

Mentat

I've just reread Dune (still just as awesome as ever), and there's something I'm wondering. Frank Herbert supposedly took the time to understand most of the subjects that came up in the book. Are the Mentats based on sound psychological principles, or did he just make them up for the hell of it? Is it possible for someone to actually become one? Does anyone with those capacities currently exist? Black Carrot 22:28, 19 March 2006 (UTC)

I thought the Juice of Sapho was a pretty important factor. That would explain why there aren't any in real life. —Keenan Pepper 22:40, 19 March 2006 (UTC)

Try some of the far eastern mystical systems of belief, Zen and Buddism should be good starting points. btw-No writer can write quality without a lot of research. But Dune is more mystical than hard science fiction. Poul Anderson, Arthur C. Clark, Isaac Asimov and Robert A. Heinlein were the patriarchs therein, and writers of today like David Weber, John Ringo, and Tom Clancy. See Science Fictions Golden Age for some other notables. Heinlein's Citizen of the Galaxy refers to 'Renshawing' which is similar to some mentat training, and Asimov wrote a short story using specially trained Kamikazi's in an interplanetary war, as their 'computational ability' was necessary for mid-course correction pioleting their personal missile. (See Baka bomb) FrankB 23:25, 19 March 2006 (UTC)

Is there anything less religious available? I can't believe Zen monks have a monopoly on this. And no, I don't think the Sapho juice is necessary in the books, it just helps. Like speed. Black Carrot 01:23, 20 March 2006 (UTC)

As a matter of fact, reading those articles(Zen and stuff), I really really don't think that has anything to do with what I'm talking about. At all. And does anyone disagree with Keenan's assumption that nobody with this kind of memory exists? I know people can to pretty amazing things. I heard awhile ago of some guy breaking the "multiplying really long numbers in his head" record, and the numbers were pretty impressive. Black Carrot 20:10, 20 March 2006 (UTC)

According to and , people exist who might be able to reach the first level of Mentat training without much trouble. Black Carrot 20:33, 20 March 2006 (UTC)

March 20

is ink harmful?

canw writing on youself with pen be harmful?--68.169.160.206 00:26, 20 March 2006 (UTC)

What kind of pen? Most of them are non-toxic, so you should be fine. —Keenan Pepper 00:44, 20 March 2006 (UTC)

It is if you draw a gang sign. Or, if you're in school, there are other things you could write with it that would get you in trouble. Black Carrot 01:18, 20 March 2006 (UTC)

Depends, do you use lead ink? LOL--152.163.100.74 03:00, 20 March 2006 (UTC)

Assuming, you are a young schoolgirl, I'm sorry to tell you, but this is another case of scaring you into not doing something. Writing on yourself in pen ink is not harmful by almost any means. By almost any, I am suggesting you haven't covered your whole body or eyes with ink. -- Mac Davis] ⌇☢ ญƛ. 04:31, 20 March 2006 (UTC)

Some markers contain xylene, which is toxic and can be absorbed through the skin. --BluePlatypus 15:42, 20 March 2006 (UTC)

How to splice together .mov files?

I have some animated clips in QuickTime .mov format and need to splice them together into one long file. Is there free-of-charge software that will do this? Seahen 01:37, 20 March 2006 (UTC)

Apparently, if you download QuickTime Alternative and install it with QuickTime Player already on your computer, then say "No" when it asks if you want to uninstall QuickTime, it will somehow unlock the QuickTime Pro features (Windows only). See this link. --Canley 02:28, 20 March 2006 (UTC)

O'RLY?--152.163.100.74 02:59, 20 March 2006 (UTC)

Jesus makes me powerful?

from where did this phrase origionate?--JMP 02:03, 20 March 2006 (UTC)

I've never heard this phrase before, and it receives no Google hits, so wherever you heard or read it may be the origin of the phrase. Seriously though, it sounds like a overly literal translation of the phrase "Lord, give me strength." which in turn is probably based on Psalm 86:16. --Canley 02:22, 20 March 2006 (UTC)

How exactly is this a science question?--152.163.100.74 02:58, 20 March 2006 (UTC)

God works in mysterious ways ;)--inks 03:52, 20 March 2006 (UTC)

That sounds like an advertisement... Jesus...makes you powerful ...--Cosmic girl 00:15, 21 March 2006 (UTC)

Maybe it is an ad. :) Superm401 - Talk 21:37, 21 March 2006 (UTC)

Superconductors

I need to clear something up, in the superconductors article it says that superconductors can hold a current for about 100,000 years. So I know this seems really obvious but could a superconductor basically be used as a capacitor for a couple megawatts give or take? Patrick Kreidt

I'm not sure if I understand the question. A decent capacitor must be able to separate charge, not conduct it. Melchoir 05:42, 20 March 2006 (UTC)

• They don't work like a capacitor, but SMES systems can hold energies in the MW-hour range. That would be a big device, though. --Bob Mellish 06:32, 20 March 2006 (UTC)

Right. Capacitors store energy in an electric field by separating charges. This is more like an inductor, which stores energy in a magnetic field by keeping a current flowing. —Keenan Pepper 13:24, 20 March 2006 (UTC)

Ignoring the semantics and addressing the implied core question "can energy be stored in superconductors", I would say yes, but it's not the best choice. Superconductors typically must be kept at low temps, which also costs energy. The ideal way to store energy differs by application. For example, water towers are an efficient way to both store clean water and water pressure (in the form gravitational potential energy), thus providing both water and pressure to the homes in a community, even when there is a short disruption in the supply. (Those communities which instead rely on electrical pumps to provide water pressure are vulnerable to both disruptions in the water supply and electrical supply, however.) StuRat 15:23, 20 March 2006 (UTC)

Psychology

I've looked all over and cannot find the answer to this psychology question.

What are some of the inaccuracies and alterations of memory?

For some reason this question makes no sense to me.

Ashley

Category:Memory disorders might jog your memory, but you should probably use examples discussed in class. Melchoir 07:07, 20 March 2006 (UTC)

The most publicized and controversial aspects of memory defects are the suppression and recall of traumatic events or the implantation of false memories by a therapist. This type of defect has led to the imprisonment of hundreds of innocent people, especially in the 1980s. See false memory syndrome. alteripse 12:18, 20 March 2006 (UTC)

I'm almost certain you're looking for examples of Memory biases, most of them should be listed in that article. -Obli (Talk) 23:45, 20 March 2006 (UTC)

Bird flu or H5N1

what is the name of the vaccination which is developed from the virus of bird flu(H5N1)itself & is used to protect the virus?

It's hard to tell from your question what you're looking for. According to our flu vaccine article, there have been several vaccines developed against H5N1 but it mutates too quickly for them to be of much use and they'd be of very limited efficacy in any future pandemic, and none seems to have an exciting name. From the "developed from the virus itself" wording, I assume you're not thinking of Oseltamivir (brand name Tamiflu), the antiviral drug that's been labelled as a "flu vaccine" by several underinformed commentators (at least here in the UK). --Bth 12:54, 20 March 2006 (UTC)

THE HUMAN BODY

Who named the organs and other parts of the human body, such as arms, legs, haart, lungs, etc.------------------

Ogg did, on a slow evening about 3.7892345 million years ago. He was entertaining his 4 year old but the names stuck and were gradually altered as his descendants separated into various language groups since then. alteripse 12:15, 20 March 2006 (UTC)

That's pretty accurate. Looks like you got it down to the month. =P —Keenan Pepper 13:22, 20 March 2006 (UTC)

I don't know...as much as I trust the good doctor, I have to wonder if every single one of those digits is significant. :o) EWS23 | (Leave me a message!) 18:20, 20 March 2006 (UTC)

We have no idea who named each body part, except for more recently discovered organs. Each word has a unique origin, and typically can be traced back to ancient languages, like Latin or Greek, although "haart" sounds Dutch to me.  :-) StuRat 15:09, 20 March 2006 (UTC)

Do all DVD-Writers support 8cm discs?

because mine keeps saying "Illegal disc".

There are three types of DVD Writers (over simplifying): DVD+ Writers will only accept DVD+R and DVD+RW discs, DVD- Writers will only accept DVD-R and DVD-RW discs, and DVD+/- Writers will accept both DVD+R and DVD+RW discs and DVD-R and DVD-RW discs. Check out whether you have a plus or a minus or a plus/minus writer and then verify which type of discs you are trying to write to. -- CSJoiner (talk) 18:41, 20 March 2006 (UTC)

Oops... I missed the part about the 8 cm disc... I'm not sure about that, so if someone else knows... -- CSJoiner (talk) 18:43, 20 March 2006 (UTC)

If it fits in the tray, it probably supports it. But you still have to worry about DVD-R/-RW/+R/+RW/-RAM formats. Do you have a manual? --Optichan 20:14, 21 March 2006 (UTC)

glue, plant tendrils BOTANY - CHEMISTRY

What is the chemical makeup of the glue that attaches the tendrils of Boston Ivy, Parthenosissus tricuspidata, to walls so permanently? Ants, and possibly other insects or mites, are in the vine when it is in it's rapid growth stage. 24.218.6.39 18:05, 22 March 2006 (UTC)

We have roots here, not tendrils like in grapewine. "Adventitious roots form along stems of climbing plants and act to stick the stem firmly to the branch or trunk. " . IANABotanist, but I would say the roots are not so much sticky. They hold by contact in micro crevices in walls, bricks, bark ... like you would do climbing. --DLL 21:49, 20 March 2006 (UTC)

Boston - sorry, I can't entirely agree, but thanks. These are not adventitious roots like those found on English ivy, Hedera helix, or Phillodendron spp. etc. They are most definitely tendrils, akin to grape vine tendrils (Parthenocissus is the grape genus) and though they do not wrap around objects for support, they do have five "sub-tendrils" with "sticky"? pads that unfurl and adhere to flat surfaces for, I am quite sure, support, not nourishment or water. Those dry, oven baked bricks facing south they climb are about as nourishing as the surface of Mars and the tendrils stay stuck years after a vine has been pulled away. The idea that micro contact, perhaps akin to a gekko's toe is a very good guess, thanks. The insects I mentioned are probably attracted to an as yet unidentified liquid at the end of the tendril as it is unfurling.

ANY BETTER ANSWERS OUT THERE? thanks.

hi: single ovary fertility ?

(Made title actually useful. StuRat 15:04, 20 March 2006 (UTC))

my question is can you still get pregnant if you have one ovary ? and also how can you know if you are fertile or not?

1) Yes, you can; your one ovary is still producing ova (hopefully viable ones, but if they're not it's because of some other, pre-existing problem). 2) Fertility tests are available over the counter that measure the levels of the various hormones involved. Ask your pharmacist. (That's fertility tests in the sense of finding-out-where-you-are-in-your-cycle, if you're wanting to find out whether your eggs are OK you'll need to see a doctor. Our article on infertility may be of interest to you.) --Bth 13:07, 20 March 2006 (UTC)

I would suspect that a woman with one ovary would typically only be fertile once every other month, instead of the usual once a month, so timing would be more critical to achieving pregnancy. StuRat 15:04, 20 March 2006 (UTC)

This is a popular misconception; it seems like common sense, but it's inaccurate. The ovaries don't alternate or 'take turns' during ovulation. There are various chemical cues which either ovary can pick up leading to the release of a mature egg. (The old wives' tale that boys come from one ovary and girls come from the other is also wrong.)

In animal studies, there is an indication that the remaining ovary is enlarged after one ovary has been removed; this result hasn't been confirmed in humans, however. The question is moot to an extent, however—the number of potential eggs is fixed by the time a girl is born. Numbering in the millions at birth, the supply is exhausted at menopause. So the removal of an ovary also removes half of the supply of potential ova, potentially hastening menopause. (There are some studies which seem to confirm this.)

Until the supply of eggs is exhausted, however, there shouldn't be a major reduction in fertility (unless whatever medical condition led to the loss or removal of the first ovary also affects the remaining one or the rest of the reproductive machinery.) TenOfAllTrades(talk) 16:04, 20 March 2006 (UTC)

There seems to be a discrepancy in your math. Even with only one million ova, used at a rate of say 13 per year, I would expect them to last 1,000,000/13 or around 76,923 years, but they only seem to last about 40 years, which would be 40x13 or 520 ova. I suspect this means that the ova aren't the limiting factor after all, but rather hormonal changes, such as decreased estrogen, cause menopause. Thus, having only one ovary would reduce the amount of estrogen produced prematurely, and therefore bring about an early menopause. StuRat 17:19, 20 March 2006 (UTC)

Usually when one of a number of glands are removed the others pick up the slack. So removal of an ovary would not necessarily result in early menopause, but result in menopause-like symptoms to a lesser degree than true menopause until the remaining ovary picked up the slack.

Video

Some hardware encoder has ASI out,what is ASI ? and where is it use ? Explain in detail. Thanks

Moon "tides"?

NASA recently published an on-line article (http://science.nasa.gov/headlines/y2006/15mar_moonquakes.htm) which stated, "There are at least four different kinds of moonquakes: (1) deep moonquakes about 700 km below the surface, probably caused by tides; ..." I do not understand the reference to tides. Surely not tides on earth; those are a result of lunar position and wouldn't seem to have an effect on the moon itself. The Misplaced Pages article on the moon makes no reference to any sub-surface water that might be involved in "lunar tides." Is there believed to be a molten core of some material that undergoes "tidal movements" as the earth & moon travel in orbit about the sun? Again, the Misplaced Pages article on the moon makes reference to the lunar "crust" but does not mention any 'ocean' of liquid beneath this crust (unless I just missed that reference). Thanks in advance, Dennis 207.5.100.27 15:22, 20 March 2006 (UTC)

Tides can and do occur even in solid bodies, though obviously to a lesser extent than in liquids (or gases). While the moon keeps (almost) the same face towards the earth at all times, and thus doesn't experience "earth tides", it still feels a tidal force from the sun. —Ilmari Karonen (talk) 16:10, 20 March 2006 (UTC)

Ah, of course. "Tidal forces" on a solid object = stress. I guess if the NASA article had used the term tidal forces instead of tides, I would have caught on. Thanks *very* much for your quick response. Dennis.

TVP vs MSG

Hello!

I have been reading some things about MSG and have found on this site http://www.happyhippie.com/ubb/Forum9/HTML/000102.html - a reference indicating that Textured protein always contains MSG

Would that also go for TVP? or are we sure that it does not include MSG?

Thank you for your response

All proteins or protein products contain some amount of glutamic acid, whose sodium salt MSG is. Whether it's there as a free amino acid or as part of a peptide chain makes little difference, since the peptide chains will be broken during digestion anyway. So yes, TVP does contain MSG. So do meat and soybeans and any other protein sources. —Ilmari Karonen (talk) 16:34, 20 March 2006 (UTC)

There should probably be a minor caveat attached to that. While digestion of nearly all proteins will yield some glutamic acid (and hence glutamate), consuming the sodium salt directly may lead to effects related to rapid uptake—a transient spike in the levels of glutamate that one wouldn't see when (comparatively) slowly digesting a meal. Compare the effects of starch and glucose, for example. Starch is made up of chained glucose units, and digestion serves to reduce it to glucose which the body can use. However, consuming one product or the other can have different physiological effects. Ingesting pure glucose will result in a much more rapid spike in blood sugar than ingesting starch.

However, except for a very small fraction of the population there appears to be no harm caused by a transient increase in blood glutamate levels. A few particularly sensitive individuals seem to experience short-term symptoms after consuming large quantities of MSG. The amount of MSG in TVP should be fairly small. TenOfAllTrades(talk) 00:01, 21 March 2006 (UTC)

Half the dry weight of the human body is protein. On average, 5.8% of that is glutamic acid. Thus, your average person is walking around with about 3 kg of pure glutamate. The vast majority of all the glutamate you get in your food is from protein, not from MSG. MSG does contain Sodium, which some people need to avoid. However, the amount of Sodium from MSG when used as a flavoring is far less than that in table salt. (Which is used in larger quantities and contains more Sodium by weight) There is no reason to avoid MSG, it's been heavily studied, and the consensus is that it's perfectly safe, and as I'm trying to say: there is little reason to assume it'd be toxic to begin with. That doesn't mean MSG isn't a public health problem.. In the sense that it distracts people from real dietary issues. --BluePlatypus 17:49, 20 March 2006 (UTC)

I personally have to avoid eating too much food with large amounts of MSG (canned & chain-restaurant soups, Chinese food, ramen, etc.) because the next day I always get severe migraines. Also, there are others who claim "Chinese restaurant syndrome". I wouldn't call it perfectly safe, but for the general public it's generally safe. — TheKMan 00:51, 21 March 2006 (UTC)

MRSA in British Hospital Staff

Has any British National Health Service Hospital ever conducted an MRSA screening programme amongst its staff, both medical and non-medical? If not, should they not do so without further delay? If yes, what were the consequences in terms of allowing/not allowing those found to be infected to continue working in close proximity to patients?

Time to suitly emphazi again -> MRSA. StuRat 17:05, 20 March 2006 (UTC)

Thank you for that meaningless comment which was patently unhelpful to me as a new user of Wikpedia. If you have anything of useful interest to add either to your comment or my very serious question I shall be most grateful for it. But please do not indulge yourself in quasi-academic twaddle. It is not appreciated. A site such as this is concerned with the dissemination of knowledge, and not the kind of deliberate fogging behaviour from which you seem to get your rocks off.

Since you used a technical acronym without bothering to explain what it means, (just like your last question on MRSA), I was nice enough to provide a link where people can find the meaning. We are doing you a favor by answering your questions, and don't forget it. Don't be rude to us or we won't bothering answering your questions at all. StuRat 17:32, 20 March 2006 (UTC)

Thank you for your prompt response. I now (think) I understand what you meant (both times) by suitly emphazi, a phrase not to be found in the Misplaced Pages Search Engine nor anywhere else I took the trouble to look. I also (think) I now understand that questionners like myself should not use technical acronyms such as 'MRSA' even though that particular one must be as commonly understood as HIV, or AIDS. I also appreciate your voluntary status and earlier advice on where to find more information on 'MRSA', for which, once again, many thanks, though it did not lead me to the kind of answer I am looking for. But it may be of some use to myself, and others similarly inexpert in using Misplaced Pages, to have a real Idiots' Guide on the page, which also included Suitly Abbrevies, Must Do's, and Don't Do's. Please accept my apologies for any offence given.

If you had Googled the words "suitly emphazi", the second result provides the answer, so I guess you didn't bother to take the trouble to look it up on Google. While StuRat was gracious enough to accept your apology, it reads to me like a very condescending way saying sorry for being rude. The question itself looks like it's part of an assignment, or something to harass the Minister of Health with during question time in parliament. To answer it would require a very extensive literature search - you'd be better off asking this question on Google answers.--inks 21:56, 20 March 2006 (UTC)

Apology accepted. Perhaps it's as well-know in the UK, but that abbrev is far less well-known in the US than others, like AIDS. You must also bear in mind that not all responses to a question will be answers. We may also need to explain the question, ask what you meant, point out why the question can't be answered in it's current form, etc. StuRat 19:02, 20 March 2006 (UTC)

Now, to get to the actual question: I don't know if there have been any MRSA screening programs in British hospitals, but can list some factors that would go into deciding whether it's wise:

1) The cost of the test, which can be purely economic or can include the medical and non-medical staff's time taken away from their duties.

2) The risk of the test. Is it safe ?

3) How widespread the disease is at present.

4) How transmissible the disease is from the medical and non-medical staff to patients.

5) How dangerous the disease would be if contracted by patients.

So, it would be advisable to perform a cheap, quick, safe test for a widespread, highly transmissible, deadly disease. Does MRSA meet those qualifications ? If so, then testing would be indicated, with the frequency of the testing depending on the answers, as well.

StuRat 19:11, 20 March 2006 (UTC)

For fun, I looked this up. Firstly, the acronym MRSA is very British, I think we call it something else in Canada (and elsewhere). Secondly, although we appreciate questions from those who think we are superhuman, we can't provide answers that don't exist on the Internet. Even if you shout and yell. These superbugs are an emerging issue, and there isn't much on them. The most important thing is to get the dang doctors to gel their hands between visits. This is apparently very difficult. Also, if I am healthy, and am carrying a few superbugs, what are you going to do? Even if you dip me in a vat of acid, my putrid body will pick up stray bacteria as soon as it's lifted. You could just shoot everybody, but that has its problems, too. --Zeizmic 20:09, 20 March 2006 (UTC)

The acronym MRSA is also used in Canada. - 216.218.44.237 22:42, 21 March 2006 (UTC)

And it's also used in the U.S. There's nothing "very British" about it. - Nunh-huh 05:16, 23 March 2006 (UTC)

I looked this up on Google News. This story contains the following quote: He dismisses the idea of routine MRSA screening for practice staff: "For a start, it would miss people who simply carry the organism on their hands - and who are most likely to pass it on." Which reinforces Zeizmic's point about the importance of getting highly trained medical professionals to follow basic hygiene advice. (Which doesn't sound like it should be that difficult, does it?) --Bth 10:45, 21 March 2006 (UTC)

I suggest a punitive approach, like cutting their pay 1% each time you catch them failing to wash their hands when indicated. StuRat 14:37, 21 March 2006 (UTC)

Actually the most common screening test for hospital employees is culturing nasal swabs (yes, infection control nurses visit the employees and stick cotton swabs up their nostrils) to test for nasal colonization with MRSA. Those employees found to carry MRSA in their nares are subjected to topical application of mupericin or some other antibiotic ointment up the nose. These measures decrease the rate of nosocomial MRSA infections, and so do handwashing programs (for a time, till everyone gets used to them). See this article (search for MRSA) for references and details. Targetted MRSA surveillance (culturing the nares of employees who work in an area of the hospital where an MRSA has occurred) is a standard infection control practice in U.S. hospitals. But routine periodic culture of all employees is not. - Nunh-huh 05:16, 23 March 2006 (UTC)

Thanks Nunh-huh for your informative (and supportive) responses. They are much appreciated.

SPDIF

Can anyone tell me what SPDIF is in relation to computers and sound cards. The article is too elaborate. --Chris 16:20, 20 March 2006 (UTC)

S/PDIF is a means of sending digital audio from one device to another. If your soundcard has S/PDIF-out, then you can plug that into the S/PDIF-in on a receiver. If you don't have any equipment with an S/PDIF port, you will have no use for it on a soundcard. --Kainaw 17:00, 20 March 2006 (UTC)

I see. I think my sound card allows for it, but I don't have anything else to connect it to. Just wondering. Thanks. --Chris 17:05, 20 March 2006 (UTC)

I've added a request to at least make the introduction of the SPDIF article less technical, see Talk:S/PDIF -- Bovineone 00:10, 21 March 2006 (UTC)

Excel macro: Finding words and neighbors using wildcards

Hi everyone,

I know code isn't answered much here, but I've got a thesis riding on this, so any help you could give would be REALLY appreciated! :)

I've got some experimental data in an Excel file with two columns: One with words and one with numbers.

What I want to do is to save all the words for which their number is > 100, AND for which there exists word* (ie: the original word with any arbitrary letters following it) with a number < 50.

So for instance, if I have

abc    65
abcd   32
pqr    105
xyz    101
xyza   45
xyzbc  35

I would like an output (anywhere) which shows

xyz    101
xyza   45
xyzbc  35

My knowledge of excel programming is really pretty basic, so I'd really love a detailed response.
Thank you so much for your help — this could save my month!
~Mary M.

It seems like the easy way to do this would be to select both columns and then choose Data --> Sort. Then sort first by the column with the word and secondly by the column with the numbers. This will arrange your columns in alphabetical order (keeping numbers associated with words). You can then scroll through the list and manually select any data that you want to keep and copy this data into your output range. There is probably a more elegant work-around that does EXACTLY what you're asking for, but this way is almost definately faster if you're just trying to analyze your data. 169.232.140.49 18:29, 20 March 2006 (UTC)

Oops... I wasn't signed in. -- CSJoiner (talk) 18:36, 20 March 2006 (UTC)

Dear Csjoiner — the problem is that the list is many thousands of items long. It would take way too long to search by hand.

Any help really appreciated! ~Mary

Maybe I'm misunderstanding your problem, so allow me to restate my understanding of it: You're trying to find rows of data in your Excel spreadsheet where the word (in one column of words) starts with some specific string of characters and where the number (in some column of numbers) is greater than some number, is that correct?

If so, the sort that I described will alphabatize all of the words, so manually selecting the block of words that you are looking for is as simple as scrolling to the first word in the list that starts with the string of characters which you are looking for and then manually selecting every entry that follows until you reach the last word that starts with the string of characters which you are looking for. (Since you're only looking for firsts and lasts, this isn't the same as checking each entry individually.) I realize that this is slightly time consuming, but it should be less time consuming than writing a macro to do it for you.

If you then need to further analyze your results, you can copy and paste your results onto a second spreadsheet and re-sort this group of results by selecting both the word column and the number column, choosing Data --> Sort, and sorting by the number column. Then, you need to simply eliminate all entries that contain numbers less than or equal to 100. Since you've sorted the list, it's again only a matter of looking for firsts and lasts... just scroll down until all numbers are greater than 100 and you're set! -- CSJoiner (talk) 19:29, 20 March 2006 (UTC)

Make a copy of your original data. For "anything with >100 in the second column", sort by the second column. Then, delete anything you don't want. I'd use a descending sort. Then on a copy of the original data, for the "anything beginning with word*", sort on the first column. Delete everything you don't want. Resort on the second column to get your >50 if you like and delete anything you don't want. You will now have the original data, a file with the >100 and a file with entries beginning with the word you like. You can cut/paste what you need into one document. --Kainaw 19:32, 20 March 2006 (UTC)

Oopses! I think that you have try this. Sort your spreadsheet by the first column.

Then add formulas there (check yourself the first line results, because one formula refer to the preceding line) :

second line, third column =IF(AND(B2>100;LEFT(A3;LEN(A2))=A2);1;0)

second line, fourth column =IF(AND(C1+D1>0;B2<50);1;0)

Copy the formulas down. Select data that bear "1" in the third or fourth column (freeze results before sorting again : "copy" and "paste special" | values). I can give more precise help but mind my Excel is in french. --DLL 21:30, 20 March 2006 (UTC)

This makes some assumptions about the data that may produce wrong results. My solution (which works basically the same way follows). -- CSJoiner (talk) 22:47, 20 March 2006 (UTC)

Okay. I understand now, and this should work.

Step One: Make a new spreadsheet. In Cell A1 write "Words", in Cell B1 write "numbers" in Cell C1 write "0" in Cell D1 write "Match Words" and in cell E1 write "Match Numbers".

Step Two: Copy all of the words and numbers into columns A and B beginning with row 2 (do not leave any empty rows).

Step Three: Select columns A and B and (from the menu) choose Data --> Sort. Ensure that "My Data has a header row" is selected, and choose "Words" in ascending order, then click okay.

Step Four: In cell C2 write IF(B2>100,A2,C1) and then copy this for every cell in the column

Step Five: In cell D2 write IF(OR(AND(B2>100,LEFT(A3,LEN(C2))=C2),AND(B2<50,LEFT(A2,LEN(C2))=C2)),A2,0) and then copy this for every cell in the column

Step Six: In cell E2 write IF(D2=0,"N/A",B2) and then copy this for every cell in the column

Step Seven: Select columns D and E and then choose "copy" then right click and choose "paste special" --> "values" then click okay

Step Eight: Select columns D and E and and (from the menu) choose Data --> Sort. Ensure that "My Data has a header row" is selected, and choose "Match Words" in ascending order, then click okay.

And that's it. The two columns D and E now contain your matches (ignore any rows with "0" and "NA" in them). -- CSJoiner (talk) 22:47, 20 March 2006 (UTC)

Hi everyone.

First, thanks so much for the adviced. It was really helpful reading what you posted, and sorry that I caused confusion by not making clear what it was that I wanted. I ended up writing a macro after all, and it was much shorter than I thought it would have to be. This macro does what I wanted, and lays all the selected words to the side in the next column, where a simple 'sort' can bring them all up to the top:

Sub Find_Words()
     ' Select cell A2, *first line of data*.
     Range("A2").Select
     ' Set Do loop to stop when an empty cell is reached.
     Do Until IsEmpty(ActiveCell)
       Dim root As String
       root = ActiveCell.Value
       If ActiveCell.Offset(0, 1).Value > 100 Then        'If root is high enough
           Dim i As Integer
           For i = 1 To 10                                'Check for derivations in a window of length 10
               Dim deriv As String
               deriv = ActiveCell.Offset(i, 0).Value
               If InStr(deriv, root) = 1 Then
                   If ActiveCell.Offset(i, 1).Value < 50 Then    'If deriv is low enough
                       ActiveCell.Offset(0, 2).Value = root      'Copy words to the side
                       ActiveCell.Offset(i, 2).Value = deriv
                   End If
               End If
           Next
       End If
        ActiveCell.Offset(1, 0).Select
     Loop
End Sub

Thanks for all your help! ~Mary

Thanks, Csjoiner! I expect every one here take our answers cum grano salis. I thought after that my formulas would be based on assumptions about data (and would be refactored, according to WP usage). Also, it is a pity that XL does not offer utilities like grep. --DLL 18:24, 21 March 2006 (UTC)

Variable vs Constant bit rate

Here's a question for all you computer geeks lurking on the Ref Desk. What are the advantages and disadvantages of constant and variable bit rate for encoding music for storage and playback on a computer, in MP3 format? (I know that, for instance, OGG Vorbis files are almost always VBR) If I understand it correctly, for space-limited applications (storing music on a hard drive), VBR beats CBR because it reduces the bit rate for 'simple' sections, reducing file size. But does it, for instance, impose an extra decoding overhead or something? Why is it not used universally? Thanks! — QuantumEleven | (talk) 17:57, 20 March 2006 (UTC)

A lot of older decoders get a bit upset with VBR - not much of a problem now, but if you're looking to use one of those MP3-CD players that were around c.2000/1, it can be an issue. Shimgray | talk | 18:44, 20 March 2006 (UTC)

There isn't really any processing overhead, the mp3 codec specifies each frame to have its own bit rate in the header. Originally, every frame had the same bit rate in their headers, but it was found that the bit rate could be varied in each frame header. So in either case, the decoder has to read the header for every frame, and therfore there's no overhead, though vbr mp3's have the advantage of providing higher sound quality for the same file size. The only problems you'll run into will be with older mp3 decoders that didn't read the headers of every frame.--Krackpipe 22:38, 20 March 2006 (UTC)

Decoding unknown program from WordPad

Can you determine what this program is for? When I open it up in WordPad, it has the following:

œËˍ�uÒ�‘X

The rest won't copy and paste here for some reason.

You are seeing garbage. You cannot view a program in WordPad. You have to view it in a hex editor. --Kainaw 18:39, 20 March 2006 (UTC)

Can't you do this simply in Notepad? Kilo-Lima| 18:52, 20 March 2006 (UTC)

You can use a program such as SysInternals' strings utility to view the printable ASCII text within a binary executable. -- Bovineone 19:07, 20 March 2006 (UTC)

To be VERY brief... Text (like you see in WordPad or Notepad) uses 7 bits. Data is stored in 8 bits. So, you cannot use WordPad, Notepad, Edit, Word, Excel, Paint, or Internet Explorer to view the 8-bit program data. You must use a Hex editor. Even then, the question "What is this program for?" cannot be answered. --Kainaw 19:17, 20 March 2006 (UTC)

It is quite likely part of a larger application and will not run on its own. What is the filename? If you Google the filename you will probably find out what it is for. --Shantavira 19:18, 20 March 2006 (UTC)

Out of curiosity, this only applies to very simple text editors? I mean, MS Word uses unicode, right? Oskar 19:47, 20 March 2006 (UTC)

Yes. I was being very brief. Unicode is 8-bit. But, you can't make sense of program code by looking at it in Unicode. You'll just get a jumbled mess of foreign characters. They won't even be all of the same language (some Chinese, some Japanese, some Taiwanese, some Swahili...) --Kainaw 19:55, 20 March 2006 (UTC)

The question is not 100% clear, but it seems to be talking about an executable file, in which case it's a compiled binary file. The only way to "open" such a file is in a hex editor, and even then it will be gibberish to all but the most expert programmer. The only real way to find out what a program does is to run it - which, if you don't know where it's from, might not be such a good idea!
Unicode is still text, just fancily-encoded text. — QuantumEleven | (talk) 19:54, 20 March 2006 (UTC)

You can open binary files in a hex editor, but you won't be able to get much information from it other than a message saying it can't be run in DOS mode and perhaps some other strings. If you really want to know what the program does, you can check if there's a Version tab in its properties dialog box or search for the filename on the Internet. --Optichan 20:08, 21 March 2006 (UTC)

If it came attached to an email message, it may be a trojan. If you're curious, you can 1. learn machine language and disassemble it. 2. run it on one of your unimportant machines, where it may do something like erase your harddrive or give access to government spooks from unknown country. GangofOne 23:17, 21 March 2006 (UTC)

heat

a silver bar 0.125 meter long is subjected to a temperature change from 200degrees c. to 100degrees c. what will be the length of the bar after the temperature change?

Is this for your physics or chemistry homework? Either way, there's a note at the top about not asking homework questions. --Kainaw 23:42, 20 March 2006 (UTC)

You might find our articles on thermal expansion and the coefficient of thermal expansion useful in doing your homework, however. TenOfAllTrades(talk) 04:05, 21 March 2006 (UTC)

Rule of thumb : the bar shall be slightly shorter.

Aditional question : Silver says the coeff. = "(25 °C) 18.9 µm/(m·K)". It cannot be linear between the absolute zero point and the melting one. The links above should explain that the coeffs are approximative, only true around the indicated temperature, and give more examples. This is important when building bridges or any big metallic structures. Where are the "real" data for calculation ? --DLL 18:17, 21 March 2006 (UTC)

Digital Universe

According to serious accepted (uncrancky) physics... is there a possibility that our universe which seems analog, is digital?...like, subatomic particles are being 'represented' in a 'digital' machine?...what do informatics and physics have to say about this?. --Cosmic girl 23:43, 20 March 2006 (UTC)

There is a possibility.

"serious accepted (uncrancky) physics"; there is no agreement on what that phrase means , so I ignore it.

• Ed Fredkin thought of it
• Stephen Wolfram seem to believe it see A New Kind of Science
• John Walker. Review of Leonard Susskind's The Cosmic Landscape: String Theory and the Illusion of Intelligent Design blog None Dare Call It Reason Makes a case for the idea that a kind of intelligent design where the universe is actually a simulation in a computer is more parsimonius (in the Ocham's Razor sense) than current physical theories.

Lots of physicist question "continuity", the idea that space-time can be infinitely divided, eg Richard Feynman. So there would be some granularity.

• Heim theory talks about such granularity. (not accepted physics, though)

Nobody knows, or if they do, they're not telling. --GangofOne 00:26, 21 March 2006 (UTC)

I suppose one could argue than particles are "digital", meaning discrete packets, whereas waves are "analog", meaning continuous. Quantum mechanics is based on "quanta", or discrete energy packets, as well. StuRat 00:37, 21 March 2006 (UTC)

hmmm...cool I c... but I meant more like... the basic 'thing' being information...like '1s and 0s'...and 'events' like... a particle 'moves' not because it actually mooooooves (lol) ...but because it ceases to exist here and suddenly appears there, but that happens so darn fast that we can't notice...do you think granularity is more plausible than continuity? or the other way around?.--Cosmic girl 00:45, 21 March 2006 (UTC)

I think maybe this theory you want to know about is called or related to the holographic theory. -- Mac Davis] ⌇☢ ญƛ. 04:53, 21 March 2006 (UTC)

The Misplaced Pages article about the holographic theory can be found at Holographic principle. --DannyZ 07:50, 22 March 2006 (UTC)

Thanx! :) ...but I think they are kind of different...but I'll take a look at the article.--Cosmic girl 16:41, 22 March 2006 (UTC)

toxic plastic

If you were to burn a credit card you received in the mail, would it release toxic fumes? Or if you threw a old bottle of Germ-X into a campfire? etc. schyler 23:50, 20 March 2006 (UTC)

Yes. Unless you burn plastics at very high temperatures (much higher than those you typically have available in a campfire or home fireplace) there will be a number of toxic products of incomplete combustion. TenOfAllTrades(talk) 00:04, 21 March 2006 (UTC)

I'm not quite sure what type of plastic is used for credit cards, but as a general rule, burning plastics in excess oxygen should yeild water and carbon dioxide, unless the oxygen supply is limited, causing carbon monoxide to form, which is highly toxic. As for the Germ-X; its main components appear to be ethanol, good old alcohol, nothing harmful about burning that, you get water and carbon dioxide there, too. The other compnent, Benzalkonium chloride, is however listed as harmful, so I wouldn't bet on vaporizing it being a good idea, but then agin, it's most likely to be found in a very low concentration of germ-x from what I've gathered. -Obli (Talk) 00:06, 21 March 2006 (UTC)

I would go with TenOfAllTrades' answer, not Obli's. You can tell you don't get complete combustion because of the burning plastic smell. If you had complete combustion to carbon dioxide and water, you wouldn't smell anything. StuRat 00:32, 21 March 2006 (UTC)

I've always heard that burning plastics release dioxin and furan compounds. --Kainaw 00:27, 21 March 2006 (UTC)

Yeah, I should probably add that it's a very theorethical answer, the other things in addition to carbon di/monoxide and water depend on what other elements are present in the plastic compound, I've just assumed Carbon and hydrogen in my asnwer, since no specific type of plastic was specified, other than "plastic card plastic". -Obli (Talk) 14:43, 21 March 2006 (UTC)

It's more difficult to avoid incomplete combustion than you think. Not only is excess oxygen required, but also a sufficiently high temperature. You don't get those in a normal fire. That's why high temperature incinerators are used, to avoid releasing pollution into the air. An alternative to a high temperature is a 100% oxygen environment. In such an environment, things are much more flammable than in normal air (including people, making this rather dangerous). StuRat 21:12, 22 March 2006 (UTC)

March 21

Will the PS3 loose the console war? GPU of the PS3?

What will happen to the video game industry as a whole if Sony looses the console war to Microsoft? It looks as though this could happen since the XBOX 360 has had a head start in sales and the PS3 has to wait till November to play catch up. Also, the PS3 will almost certainly be more expensive than the XBOX 360. I don't know if gamers are willing to pay $500-600 for a "superior product" as Sony claims.

Also, is there any truth to the rumor that Sony was going to develop the graphics for the PS3 but soon discovered that the Cell processor was not powerful enough and Nvidia had to bail them out by stuffing a 7800GTX into the PS3 and renaming it the "RSX"?

If PS3 turns out to be too expensive and ends up failing miserably, the victory will be going to the Nintendo Revolution. XBox has never been popular in Japan, and most likely never will - and since Japan is probably the most important territory, they'd only be able to win on a national scale.

I honestly think Revolution is the biggest competitor anyway, though it does depend on them being able to make good use of the controller. If they can do that, though, they stand a good chance of gaining MASSIVE sales.

As for the rumor, I haven't heard of it, and I can find nothing supporting it here on the Wiki. Of course, that doesn't necessarily mean it isn't true, but I doubt it. The processor is powerful enough to make full-res HDTVs with PLENTY of power, see Cell (microprocessor). --Pidgeot (t) (c) (e) 01:57, 21 March 2006 (UTC)

Somhow I feel this has nothing to do with Science. More like Sociology or something. Either way, this discussion should not take place on this page. I'm not totally sure, but I think this discussion could go on some other special page like the Misplaced Pages Millionth Topic Pool. schyler 02:25, 21 March 2006 (UTC)

I disagree. Which of a list of competing electronic products wins is due, at least in part, to the level of technology each can offer. StuRat 03:12, 21 March 2006 (UTC)

In that way you are right. I just saw this discussion turning into a XBox 360 fans vs. PS3 fans vs. Revolution fans. But conserning the technological aspects, I can see that fitting on this page. schyler 12:56, 21 March 2006 (UTC)

elevation

how is elevation measured?

The article Altimeter describes a few methods. Melchoir 01:04, 21 March 2006 (UTC)

And it's typically described as feet or meters above sea level. StuRat 01:27, 21 March 2006 (UTC)

When measuring altitude, but when measuring elevation it's usually height above the geoid. EricR 02:01, 21 March 2006 (UTC)

There are lots of ways to measure elevation.

• use your GPS receiver
• use a clinometer or theodolite
• by celestial observation
• measure the boiling point of water to get the pressure altitude
• throw something off the top and time the fall

Elevations on the earth's surface have probably been measured by all those methods. Take a look at Shuttle Radar Topography Mission to see a good way of doing it today. EricR 01:37, 21 March 2006 (UTC)

And it's shown on a topographical map with elevation contour lines. StuRat 02:05, 21 March 2006 (UTC)

Time to repeat a classic tale: Teacher says Explain how to use a barometer to determine the height of a tall building. The student wrote, Tie a rope around the barometer, lower it from the top of the building until it hits the ground, make a mark on the rope, pull it up, and measure the length of the rope. (There are other ways of doing this.) This put the teacher in a bit of a bind. He called in one of his colleagues, and explained what had happened. The colleague said, In a way that demonstrates your knowledge of physics, explain how to use a barometer to determine the height of a tall building. The student said, Go to the top of the building with a barometer and a stopwatch. Drop the barometer, and measure the time before the barometer splatters on the ground beneath. Then use the formula y = 1/2 at2 to calculate the height of the building. The teachers conferred and gave him almost full credit. The teacher asked what some of the other ways were: Go outside on a sunny day, and measure the height of the barometer, the length of the barometer's shadow, and the length of the building's shadows, and use ratios to determine the height of the building. This probably isn't the best way, but go into the basement, knock on the superintendent's door, and say, 'Mr. Superintendent! I have a fine barometer for you if you will only tell me the height of the building!' WAS 4.250 12:30, 23 March 2006 (UTC)

iTunes Glitch

Whenever I try to download pod-casts or see what is in the music store, I see this message in a pop-window: "iTunes could not connect to the Music Store. Make sure your network connection is active and try again." My Internet connection is fine and I have been seeing this message for three days. Also, my version is the latest — 6.0.4.2.

Can anyone offer suggestions and advice?

Patchouli 01:43, 21 March 2006 (UTC)

Windows or Mac? Did the error occur since you updated iTunes to the latest version. Have you installed any other software or utilities in the last week? Have you installed or activated a firewall or any security software like Little Snitch? Are your network settings using your ISP's proxy server? --Canley 02:09, 21 March 2006 (UTC)

• I have Windows XP Media Center Edition. I updated my iTunes yesterday and this hasn't fixed the problem. I only remember having installed the Google Web Accelerator, Shockwave, and everything from the Windows Update site of Microsoft.

My Windows firewall is off and the sole firewall on my computer is Norton Personal Firewall. Since the Norton Firewall is for Internet Explorer browsing, then it shouldn't affect iTunes.

Wait a minute, I just disabled the Norton Firewall, and then it worked.

Patchouli 02:47, 21 March 2006 (UTC)

According to this Apple support document, you need to download the latest firewall definitions from Symantec to allow the iTunes Music Store to access the internet. --Canley 05:01, 21 March 2006 (UTC)

• Thank you for imparting your knowledge.Patchouli 07:20, 21 March 2006 (UTC)

Just a comment on "Since the Norton Firewall is for Internet Explorer browsing..." The purpose of a firewall is to block unexpected attempts to connect to your computer from outside, and sometimes to stop your computer connecting unexpectly to outside. This isn't really anything to do with Internet Explorer. Typically, the firewall is going to allow Internet Explorer to connect to the internet, because it needs to do that so you can browse. Blocking all other programs is normal, and you may need to manually allow them to do their work, if you want them to access the internet. The idea of a firewall is (a) to stop bad guys reaching your computer and (b) if the bad guys are already there, stop them calling home with all your private information. Notinasnaid 12:18, 21 March 2006 (UTC)

Organic Synthesization

hello Give four basic products of organic synthesise and three of their application

Organic synthesis? Melchoir 04:01, 21 March 2006 (UTC)

Plant Fertilizer

What does "Total Nitrogen" do for house plants? What does "Phosphoric Acid" do for house planets? What does "Soluble Potash" do for house plants?--209.89.235.178 04:28, 21 March 2006 (UTC)

Check the nitrogen, phosphoric acid, potash, and fertilizer articles and come back if you aren't satisfied. -- Mac Davis] ⌇☢ ญƛ. 04:50, 21 March 2006 (UTC)

Confusing

This is in the cell (microprocessor) article:

Sony's PlayStation 3 video game console will contain the first production application of the Cell processor, clocked at 3.2 GHz and containing seven usable SPEs. An eighth will be manufactured, but one will be disabled at the factory in order to allow Sony to increase the yield on the processor manufacture.

Could someone explain this statement? --Shanedidona 05:01, 21 March 2006 (UTC)

Defects in a semiconductor IC are typically a bad spot on the die, due either to an irregularity in the silicon crystal on which it was deposited, or a defect in the depositional process. That bad spot makes the circuits around it, and any depending on them (and any on them, etc.) inoperable. It sounds like Sony will put eight SPEs on the die. If one of those SPEs is knocked out by a defect, seven will remain. They've designed the whole chip such that, when they detect one SPE is bad during manufacturing-test, they can set the equivalent of a jumper (in practice I think they'll make or break a solder connection in the ceramic package that hosts the chip). The chip is wired such that it has seven logical SPEs, each of which is wired to one of the eight available physical ones. The setting of the pseudo-jumper makes it rewire slightly, to use the "spare" SPE, rather than the defective one. So long as only one SPE is defective, the whole chip is still operational. This increases yield because it means that lots of defects that would have killed a chip with no redundancy now don't. Some components aren't redundant, and they're still susceptible to defects which span two SPEs, or to multiple defects, but I'm sure they've analysed the typical defects that arise from the process they're using and have calculated that the gains in yield earn them more revenue than the additional costs associated with this redundancy. I think you'll see a lot more of this kind of thing, mostly in ICs where there are many identical subsystems (particularly memory chips); increasing yield by further increasing the quality of the silicon or the cleanliness of the cleanroom is very epensive (as semiconductor companies already do a very good job of that, and those errors that remain are tough to fix), whereas wasting a few percent of the floorspace on each chip (for a spare element that generally isn't needed) is a pretty low cost. -- Finlay McWalter | Talk 11:05, 21 March 2006 (UTC)

Differences between pass extinctions and the current one

There have been many extinctions in the pass and according to some scientists, there is one going on right now. If there are any differences between pass extinctions and the current one, what are they? (example: pass ones are largely natural, but this one is probably due to human causes)

Thanks! Alex Ng 05:53, 21 March 2006 (UTC)

The word for things from before is "past", not "pass". Current extinctions are largely the result of human intervention while past extinctions were the result of natural forces, like a new species which outcompetes the old one, giant meteors, climate change, and changes in the percentage of oxygen in the air. StuRat 11:22, 21 March 2006 (UTC)

Also, I suspect you meant to ask about "mass extinctions", as extinctions of a few species happens all the time. StuRat 11:30, 21 March 2006 (UTC)

(after edit conflict) I presume you mean "past" extinctions? We have a pretty good article on the subject: extinction. Your question is difficult to answer precisely because extinction happens all the time, usually at a more-or-less constant rate. Exceptions to this rule are mass extinction events, which very suddently clobber an enormous number of species (the most famous is the Cretaceous-Tertiary extinction event, the one that killed the dinosaurs), see Extinction event. Note that "sudden" is in geological time - ie we could be talking hundreds or thousands of years. Over the last several hundred years, the extinction rate has been increasing sharply due to human activity, so sharply in fact that some some are calling it the Holocene extinction event, caused by human activity. — QuantumEleven | (talk) 12:40, 21 March 2006 (UTC)

The difference is past mass extinctions were not caused by one species taking over in population, modifying land and other eco-niches for its own use and propagation. Before, the extinctions made "living space", in ecological niches, for new developments of new species. The current takeover by one weed species isn't allowing room for new things. Survival of the weediest. So it is a kind of "end of history". Better to bulldoze the rain forest to raise food-cattle for hamburgers, than allow others to live and let-live. It is the information (noosphere) manipulation and transference that makes this possible. The dominant species even has satellites to watch everything, looking for resources to exploit, and inefficiences to correct. It devotes a large part of its life cycle to transfering symbols and symbol-mainpulation tools to the next generation, without also transmitting an overview that would show that continued life-worth-living depends on the continuation of other genelines. In fact, I suspect your very question arose in such an information-transference context, a school, where you are being trained to answer questions posed to you, such as this very homework essay question, where you are being trained to take your place in the machine, just as the internet, and wikipedia, and this very answer you are now reading are part of the process. Carry on, soulless zombie-robots. --GangofOne 23:02, 21 March 2006 (UTC)

Several mass extinctions in the past have been attributed to human action, though I believe there is now some dispute over this. In particular I mean the extinction of a huge proportion of the large animal species of the Americas when human hunter gatherers first moved there. I think there was a similar occurrance in the Antipodes too. AllanHainey 16:15, 22 March 2006 (UTC)

Location of the Earth's (ellipsoid) center of gravitation

To a close approximation, the Earth's shape is an oblate spheroid Becauase of this non-spherical shape, the point of grip of the Earth's gravitation does generally not coincide with the Earth's center of mass. For instance, for an object resting on the equator, the point of grip of the Earth's gravitation is about 10 kilometers away from the Earth's center of mass. This is of course related to the fact that the polar radius is about 21 kilometers less than the equatorial radius

Is there a mathematical formula that gives the point of grip of gravitation as a function of latitude? And a more specific question: for an object at rest on one of the poles, does the point of grip of gravitation coincide with the center of mass?

I have done quite a lot of googling to find an answer to the questions above, but no luck. 'point of grip of graviation' is not standard terminology, I suppose. Other variations, such as 'center of gravitation' were unsuccesful too. --Cleonis | Talk 07:31, 21 March 2006 (UTC)

I'm not sure what you mean by "point of grip", but I do know that in general, the center of mass and the center of gravity do not coincide. The center of gravity of a body is a function of the gravitational field it is in, as well as its mass distribution. So one could figure out the center of gravity of the Earth in the moon's gravitational field, or the sun's field, or the total field. The center of gravity indicates where the net force acts from another body's attraction. But small objects don't create a field enough to attract the Earth, and so this issue doesn't arise. My weight vector points exactly towards the center of mass of the Earth. You're not looking for a difference between the center of mass and the geometric center, are you? That happens when density is not uniform. -lethe 09:40, 21 March 2006 (UTC)

The Earth (oblate ellipsoid) has cilindrical symmetry, from that it follows logically that the Earth's center of mass coincides with the Earth's geometrical center. (The Earth's density is not uniform, but the density distribution is cilindrically symmetrical.) That is clear.

I choose to define 'weight vector' as: the vector that is precisely opposite to the Normal force that the Earth exerts on an object that is resting on the Earth's surface. Obviously, the thus defined weight vector does not point towards the Earth's geometrical center.

I lay down another definition: 'true newtonian gravity': purely the gravitational force that is exerted by the Earth on an object resting on it. I should point out that gravimetric readings by measuring instruments that are co-rotating with the Earth (resting on the Earth's surface), measure a combination of two things: the gravitational acceleration minus the instrument's own centripetal acceleration. (See the Equatorial bulge article). In other words: gravimetric instruments measure the weight vector.

The weight vector and true newtonian gravity do not point exactly in the same direction (they do point exactly in the same direction on the poles and on the equator, of course). Neither of the two points exactly to the Earth's geometrical center. (Of the two, true newtonian gravity points closer to the Earth's geometrical center.) --Cleonis | Talk 10:55, 21 March 2006 (UTC)

OK, so the problem is that the graviational force will not always be normal to the surface, which complicates things. Yeah, I don't know nuthin about that. I guess my above comments were not so helpful. Sorry. -lethe 15:07, 21 March 2006 (UTC)

See Gravity anomaly. This is the difference of actual gravity from the theoretical ellipsoid. This dominated by bumps on the core, ore bodies, etc. We use this in geophysics all the time. --Zeizmic 12:10, 21 March 2006 (UTC)

I am looking for information about the difference between the theoretical sphere and the theoretical ellipsoid. I suppose information about that difference is so hard to find because in practice geophycisists do not need to consider that difference. --Cleonis | Talk 13:37, 21 March 2006 (UTC)

Not sure exactly what you are after, but here is a resource which might help. If you are trying to shift the the geodetic coordinates between points on the reference ellipsoid (a spheroid) to points on a sphere with the center offset, you could use a datum conversion. If you just want to translate the center, you use a 3 parameter datum conversion or Molodensky datum conversion. For more complicated transformations you use a 7 parameter datum conversion. Not sure if that's what you want, but something on that colorado.edu page should help. EricR 14:54, 21 March 2006 (UTC)

Would this diagram help explain what your are after? It sounds like you are trying to find the tangent of a point on a sphere given a point on the ellipsoid. Not sure which sphere you are interested in though. What are the sphere's center and radius relative to the ellipsoid? EricR 16:04, 21 March 2006 (UTC)

That colorado.edu site uses the word "Datums". Really annoying, I keep trying to find the "Edit this page" button. GangofOne 22:12, 21 March 2006 (UTC)

Thanks, EricR for pointing out the diagram There is the reference ellipsoid, and for every point on the reference ellipsoid there is the vector of the normal force. As the diagrams shows, the point of intersection of the normal-to-the-ellipsoid and the plane-of-the equator does not coincide with the center of the Earth. For the rest: see my reply to GangOfOne. --Cleonis | Talk 14:28, 22 March 2006 (UTC)

About the original question, "point of grip", (which I don't understand yet), you say "for an object resting on the equator, the point of grip of the Earth's gravitation is about 10 kilometers away from the Earth's center", how did you compute that? Is it on the line throught the center? Is this a concept that is intended to include centrifugal effect, or exclude it? Is 'point of grip' intended to be the point where if all the mass of the planet where put as a point particle, gravity would be the same at the test position? GangofOne 22:12, 21 March 2006 (UTC)

My intend is to not take centrifugal effect into account. You are correct in surmising that I mean: the point where all the mass would have to be concentrated to exert the same gravitational force as the reference ellipsoid does (in the case of an object that is at rest on a non-spinning reference ellipsoid).

Approximate calculation for object at rest on the equator:

An object at rest on the equator of a non-rotating celestial body with the shape of the reference ellipsoid, has a higher gravitational potential energy than the same object at rest on one of the poles. I will call the difference in gravitational potential between those two locations the 'pole-equator potential energy'

An object at rest on the equator of the spinning Earth has a velocity of about 465 m/s. This corresponds to a kinetic energy of about 1.1 x 10^5 joule per kg of mass.

It is a theorem of the dynamics of rotation that in the case of perfect circular motion the kinetic energy and the potential energy are equal in magnitude. So in this case the pole-equator potential energy equals the kinetic energy.

the 1.1 x 10^5 joule per kg of mass corresponds to a difference in height of about 10 kilometers.

About that 'equal in magnitude' of kinetic energy and potential energy. Here, the potential energy is defined as follows: the integral of the total amount of work that the centripetal force would do if it would be allowed to pull an object all the way to the axis of rotation. --Cleonis | Talk 14:28, 22 March 2006 (UTC)

EricR, GangOfOne, thank you for taking an interest in my question. I have copied my reply to GangOfOne to my talk page. The huge size of the reference desk page is cumbersome, can you please add any further comments on my talk page? --Cleonis | Talk 15:01, 22 March 2006 (UTC)

About PIC16F877 microcontroller

Iam new to electronics.I need beginers and complete tutorial on PIC16F877 ,its instruction set,its assembly level programming and examples.Request to reply soon to <email removed for the sake of your inbox>

Here are a few links that may be more or less useful: . HTH, HAND. --Bth 10:29, 21 March 2006 (UTC)

relativistic angular momentum of a rotating body

I would like to figure out what the angular momentum of a rotating rigid body is, if it's rotating at relativistic speeds. Now, I know the formula for angular momentum is the same r×p in relativity. (Or better, xp – xp, since there's no cross product in Minkowski space, but whatever). I can use this to calculate the angular momentum of, say, a spinning disk. The problem is that I expect that the binding energy of the disk (which must grow as the rotation increases) makes a nonnegligible contribution to the angular momentum. But I don't know how to go about estimating that contribution. I was sick the day we covered special relativity of rigid bodies. Any help? -lethe 08:38, 21 March 2006 (UTC)

Quite possibly the concept of a spinning rigid body cannot defined at all in relativistic physics, which then implies that a concept of 'angular momentum of a rigid disk' cannot be defined in relativistic physics. See Ehrenfest paradox --Cleonis | Talk 09:01, 21 March 2006 (UTC)

Yeah, I have some idea that rigid bodies are tricky in relativity. I think Born made some method for describing rigid bodies under linear acceleration, but I don't know the details, and I don't know about rotating bodies. How about this as a warm-up: two massive point particles connected by a weightless spring, rotating around their center of mass. -lethe 09:14, 21 March 2006 (UTC)

Black holes have angular momentum. The problem is if a sun has a rapidly rotating outer surface, it is unlikely to collapse into a neutron star as the surface has to be moving slower than the escape velocity of the sun.

grey / white dot in the pupils

greetings .. my question is regarding a white or grey dot in the pupils . what is that ? and what does it do in there ? is it bad ? is it treatable ? ,,, thank you for your time.

First, could it be a spot on the contact lens ? If not, I would suggest going to an eye doctor to have it checked out. StuRat 11:16, 21 March 2006 (UTC)

How long has it been there? I think you should see an optician in case it's a cateract developing. --Username132 (talk) 12:03, 21 March 2006 (UTC)

This appears to be a BE/AE difference. In the U.S. you would want to see a ophthalmologist or maybe and optometrist. Rmhermen 18:07, 21 March 2006 (UTC)

Computers

If a USB 2.0 is faster than USB 1.2 then how can one USB 2.0 hub provide four simultaneous access of USB2.0 ports through one USB2.0 port from the computer?

I guess they wont all be operating at full speed all of the time. Most of the time though, the devices plugged into USB aren't even capable of using up the full bandwidth. What devices plugged into the hub do you use? --Username132 (talk) 11:57, 21 March 2006 (UTC)

I dont have a hub..just asked the question out of sheer curiousity.Also what about FIREWIRE hub?I guess that MAX speed of USB2.0 divided by 4 is the answer.

Physics:-Relativity

According to relativity(mass dilation),our mass increases as we gain a higer velocity and vice versa.So suppose a particle were to increase its velocity and decrease its velocity(positive and negative acceleration)at regular intervals,would that cause a gravity wave?Also would a body moving at a constant angluar velocity(uniform circular motion)that experiences a constant linear acceleration put out such waves of disturbances in space time?--61.1.131.70 11:54, 21 March 2006 (UTC)

Well mass doesn't have direction (it's scalar) so I guess it's the magnitude of the velocity which determines the mass and changes in direction (which is why it's said to be 'accelerating') won't have any effect on the size of the mass. The fact that it's moving around and that its gravitational draw on something are inversely proportional to its distance away from that something might cause a "gravity wave"? --Username132 (talk) 12:02, 21 March 2006 (UTC)

Any system of masses with a time-varying quadrupole moment will produce gravitational radiation ("gravity waves" is a common phrase used to refer to such radiation, but is potentially misleading as that term has a long history in another context; "gravitational waves" is preferred). Note that the size of gravitational waves is absolutely minuscule except for high mass, high acceleration events like neutron stars spiralling in towards each other. So the question becomes to determine whether your examples have a time-varying quadrupole moment. I have a feeling that neither of your examples qualifies as you're talking about point particles, but that if they became prolate or oblate spheroids, or long rods, or some other thing with extent and non-spherically-symmetric shape, they would. However, I haven't done any detailed analysis and my GR is rusty so take these as the hunches they are. See the "Sources of Gravitational Waves" section of the gravitational radiation article for more. --Bth 12:56, 21 March 2006 (UTC)

As Bth writes, a necessary condition is a time-varying quadrupole moment. So two neutron stars orbiting each other in circular orbits will not lose energy in the form of gravitational radiation, but if their orbits are elliptical then they will. By contrast: a negative electric charge orbiting a positive electric charge will always radiate electromagnetic energy. Another example is that electrically charged particles that are driven to oscillation lose their energy again by radiating electromagnetic waves. Mass that oscillates in the same way does not produces gravitational radiation. --Cleonis | Talk 14:20, 21 March 2006 (UTC)

difference between a sunglass and an anti-reflective coating eyeglass

What is the difference between a sunglass and an anti-reflective coating eyeglass?

Is the eyeglass with anti-reflective coating the one which we use while using a computer?

Is there any type of special eyeglass which can be used while using a computer?

What glass material is the anti-glare screen used before PC monitors made of? Are they made of anti-reflective coating material or are they made of the material used in sunglass?

Sunglasses limit the amount of light that passes through the glass, while anti-reflective glass limits the amount of light that reflects off the glass. For anti-glare screens the material doesn't matter, so long as the surface is rough. This causes reflections to be diffuse rather than bright and sharp. Diffuse reflections are not as distracting. StuRat 12:58, 21 March 2006 (UTC)

Just to add slightly to StuRats comments. There are three things that can occur to light when it hits the surface of the eyeglass lense (or the computer monitor, or a window, etc). The light can be reflected, transmitted, or absorbed. Sunglasses increase the absorption (and sometimes the reflection) to reduce the transmission. Antireflective coatings (typically a thin layer of titanium dioxide on sunglasses) increase the transmission and reduce the reflection. And antiglare coatings are, as StuRat says, a rough surface (usually a polymer for computer screens) that scatters the reflected light so it isn't so bright. If you are looking for a way to reduce eye strain while using the computer, my suggestion would be short breaks every once and a while with some eye exercises (you can find ideas all over the web). Chapuisat 18:41, 21 March 2006 (UTC)

Question about phishing

I just received yet another phishing attempt, and there's one thing I don't understand. When I mouse-over the link that purportedly goes to chaseonline.com, where I could put my non-existent Chase bank account number, I see the name of the phishing site, http: //www.chaseonline .chase.3y-cgi. com/redirect.php. My question is: isn't the person who registered the domain easily traceable? When I do a whois for 3y-cgi.com, I get a name and registration info (including the fact the the domain was only created three days ago). Obviously this name could be faked, but at some point doesn't the person need a valid credit card to register a domain? How come these people don't get thrown in prison the very next day after sending out phishing attempts? — Asbestos | Talk (RFC) 14:00, 21 March 2006 (UTC)

Yes. They are easily traceable. But, there are many things that work in the favor of the criminal. If they are overseas, local police cannot touch them. If they are local, local police have to do an investigation - which takes months and months and months... By the time anyone gets around to trying to arrest them, they've moved. Finally, the name/address you got from the domain is most likely fake. With all the "buy a cheap domain" sites, it is very easy to purchase one with fake information. Then, with all the "get cheap hosting" sites, it is very easy to get hosting with fake information. --Kainaw 14:06, 21 March 2006 (UTC)

Think this through one more time... What makes you think they don't use the volumes of stolen information to further their efforts? Not that i'm in that business, but if i were that would seem like a no-brainer. They can use layers upon layers of cracked 'zombie' computers to make their ultimate location untraceable, and with all the personal and financial information they steal they simply use some of it to 'reinvest' in their efforts by buying domains, hosting space, whatever. Who cares if they get shut down a day later and some stranger gets a knock on the door from the FBI (not even likely). They just click a few buttons and have a whole new operation running in a matter of minutes. --Jmeden2000 15:44, 21 March 2006 (UTC)

Akrit Jaswal

anyone know anything about this guy Akrit Jaswal? look him up on google news

Erm, I know there was a TV programme about him on Channel Five in the UK last night, "Extraordinary People: The Seven Year Old Surgeon". Unfortunately, I didn't see it (I was at a salsa class), but is their page on the show any use to you? What in particular do you want to know about him? (Our article is sadly only a stub, if you find some interesting material do consider adding it.) --Bth 16:35, 21 March 2006 (UTC)

medical condition

I have been told that there is a condition where someone can be born with one buttock instead of two. I have looked all over the web and can not find anything on it. Was I misinformed or is it actually a condition?

Thank you Jessica

I can picture one being smaller than the other, but if one was completely missing, what would that mean ? The hip bone showing right through ? StuRat 16:47, 21 March 2006 (UTC)

We can name it, aplasia glutei maximi, but it appears we have no article on it. alteripse 17:00, 21 March 2006 (UTC)

And who's going to be first with the obligatory Monty Python (or perhaps Coneheads) reference? —Steve Summit (talk) 19:19, 21 March 2006 (UTC)

There was an episode of King of the Hill about this. - 216.218.44.237 22:33, 21 March 2006 (UTC)

This is an "assinine" question. Uh, huh huh. Brian G. Crawford, the so-called "Nancy Grace of AfD" 02:43, 22 March 2006 (UTC)

Back on the farm we had a calf born with no butt-hole, just an oval of pink skin. That is a lot like what Jessica is asking.

Perpendicular universe

As opposed to parallel universes, are there any references to perpendicular universes? Like one universe intersecting another and causing implosions ans explosions and all kinds of space-time anomalies?— Preceding unsigned comment added by 4.19.93.2 (talk • contribs)

• Um, that's not what parallel universe means, universes don't make any sense in 3D, so the idea of orthogonal universes is kind of.... weird--152.163.100.74 17:40, 21 March 2006 (UTC)

• oh and try this--152.163.100.74 17:40, 21 March 2006 (UTC)

• Oddly, that google definition sources a non existent en.wikipedia article--152.163.100.74 17:41, 21 March 2006 (UTC)

The article was deleted January 11. How often does Google update that? --Optichan 20:19, 21 March 2006 (UTC)

Some ideas in the (highly speculative) field of brane cosmology might qualify as fitting the general idea of "intersecting universes and their consequences". --Bth 17:50, 21 March 2006 (UTC)

True, but since "parallel" universes have nothing to with geometry, wouldn't the points of intersection still fit the definition of a parallel set of universes, rather than forming the basis of a new term?

In fact, don't parallel universes actually refer to branch points, making them, mathematically speaking, fractals, which would have to be seen as specifically non-parallel?--152.163.100.74 17:57, 21 March 2006 (UTC)

Yes, perpendicular universes would be the same thing as parallel, they don't have to do with geometry, and physicists tend to represent them as "bubbles in a foam" anyway. Parallel just means time is the same at both, even though that is not necessarily true anymore. -- Mac Davis] ⌇☢ ญƛ. 21:05, 21 March 2006 (UTC)

Hmmm I thought a universe was parallel because actions in one universe do not affect the other, except where transdimensional gateways allowed travel from one to the other. A perpendicular universe, hmmm. Try reading a sci-fi short story called Highway J. This allowed a section of space to be rotated so the time axis was transposed with one of the mundane axes in the normal universe. This allowed a person to move on the time axis by moving along the apparent mundane axis.

I don't know about anybody else, but sometimes I think we're living in a skew universe. —Steve Summit (talk) 17:00, 22 March 2006 (UTC)

Combustion products of nylon 6,6

There are no references in the MSDS for products given off by polyamides (nylon 6,6) when they are burned. Where might I find this information? Frank W. Croft Safety & Training Coordinator Fenner Drives (email and other identifying information removed as spam and privacy protection)

According to :

HAZARDOUS DECOMPOSITION PRODUCTS: Burning may produce CO, CO2, NOx, HCN.

Here's a Material Safety Data Sheet (MSDS):

StuRat 19:57, 21 March 2006 (UTC)

Blender problem

It's a question to people who are writting Blender tutorial: "Blender 3D: Noob to Pro". What should I do, if I cannot make two colours in Blender? I added a new material in "Link and materials" tab. When I want to add another one material, it becomes the same as prior one. I'm waiting for quick reply. Thank's in advance.

Erm... this is Misplaced Pages, the tutorial you're talking about is on Wikibooks: Blender 3D. You should go and ask there, probably on the book's talk page. — QuantumEleven | (talk) 07:22, 22 March 2006 (UTC)

Why does this work?

1. While sitting at your desk, lift your right foot off the floor and make clockwise circles.
2. Now, while doing this, draw the number "6" in the air with your right hand. Your foot will change direction.

Something to do with the area of the brain that controls movement on that side of the body? Dismas| 20:40, 21 March 2006 (UTC)

The brain sends many signals at once on an unconscious level, but only one complex voluntary sequence can typically be sent at a time. If you practiced enough, you could teach your brain to do this, however. StuRat 20:54, 21 March 2006 (UTC)

Whoa, that is sweeeeet. -- Mac Davis] ⌇☢ ญƛ. 21:09, 21 March 2006 (UTC)

Isn't that just a question of coordination? --BluePlatypus 23:00, 21 March 2006 (UTC)

I can do it now, with about one minute's practice. I suspect it's just the "rub your tummy, pat your head" thing; as someone said, coordination. --George 05:56, 22 March 2006 (UTC)

Gluclose->GalactoseGalactose-March_21-2006-03-21T21:21:00.000Z">

what happens to glucose or galactose when the Cu+2 in benedict is reduced? Shauna

Sounds like a homework question (see above). I'll give you a hint: If the copper is reduced, the other reagent must be ___? --BluePlatypus 21:21, 21 March 2006 (UTC)Galactose"> Galactose">

Increased?

This is a specialized chemical use of the word reduce. See Redox. —Keenan Pepper 03:41, 22 March 2006 (UTC)

Data replication

I'd seen an article an year ago about efficient data replication in lossy networks by means of first "breaking" up the data in several duplicated data chunks (say n chunks) and then these 'n' chunks are transmitted. As long as the receiver is able to get a fraction of those chunks, then the data can be "recreated" from those 'm' chunks. Now, i'm not able to remember where i read this or what it is called. Could anyone please shed some light on this technology? Thanks! Vasu

possibly an error-correcting code? EricR 21:45, 21 March 2006 (UTC)

The accurate term is probably Forward Error Correction, but unfortunately the article isn't very thorough. 84.239.128.9 21:50, 22 March 2006 (UTC)

This was not at the level of error correction. It was at a higher layer wherein the data would get divided into chunks which together would exceed the size of the original data. This is due to the duplication of parts of the data across the chunks. So, as long as the receiver would get a minimum number of any data chunks, it would be possible to deduce the original data content.

If you mean "not at the level of bytewise error correction", no, but what you're talking about here is a sort of "filewise error correction". The basic idea is very simple. For example, I might break a file up into, say, 512-byte chunks, and for each five chunks A, B, C, D, and E in the input, transmit or store an extra, sixth chunk F where

F = A ^ B ^ C ^ D ^ E

where ^ is the XOR operator (applied across every bit in every byte in the chunks). I repeat this with the 6th-10th chunks in the input (resulting in an extra 12th chunk in the output), the 11th-15th, etc. Then, if (for example) chunk C gets damaged in transit (which I'll need some kind of per-chunk checksum scheme to detect) I can reconstruct it as C = A ^ B ^ D ^ E ^ F. (But if two chunks out of any six get damaged, I'm out of luck.) This technique probably goes by various names; I call the groups of chunks XOR redundancy groups (which I see from the red link color we don't have an article on).

I first heard about this techinique in the VMS BACKUP program, but I'm sure it's been used elsewhere. I keep meaning to write data to my archival CD's this way, since CD's are known not to be a perfectly stable long-term archival medium. —Steve Summit (talk) 23:10, 21 March 2006 (UTC)

I don't know if there is a specific name for it, but its the same idea that's used in RAID 5. Basically, you decide how much overhead you want and the tolerance of the system to unit failure is equivalent to that overhead, because parity data is dispersed and allows for recreating one element the size of the overhead, if any single element is lost. The Raid 5 article has some insight into techniques and theories. --Jmeden2000 18:16, 22 March 2006 (UTC)

Canadian health care: Availability, waiting times

I have fairly serious health problems, since I broke my back last year, and I'm considering moving to Canada. The Health care in Canada and Canadian and American health care systems compared didn't give me a good idea of how things compared from a patient's point of view. Is there a longer wait time for services in Canada? (One of the articles alluded to this, but said nothing concrete). Will it be harder to find medical specialists, such as a physiatrist? What differences would I expect as a patient with specialized medical needs? -- Creidieki 23:03, 21 March 2006 (UTC)

Just hope you don't break your hip too—see (admittedly not the most neutral of sources) --zenohockey 23:34, 21 March 2006 (UTC)

Canada's a big country; health care is provincially administered, and even within a province conditions in one city may be different from another. You really need information about the specific place or places you are thinking of moving to. For that matter, unless we know about conditions wherever it is you are moving from, we can't tell you what's different, can we? --Anonymous, 05:30 UTC, March 22, 2006.

If you have $$$, you can get much faster service in the USA (or India for that matter). Health care services in Canada do vary from province to province. Physical therapy and rehabilitation is one of those things that tends to vary. What Canadian "universal" health insurance means is that you will be covered for most services rendered in a hospital (such as most surgeries) and visits to a GP/family doctor or specialist. Some things are not covered, such as cosmetic surgery. Generally, it is easier to find a specialist in the larger cities than in rural areas. - Cybergoth 02:10, 25 March 2006 (UTC)

Medicine - Hole in one's throat

Hi there! I would like no know the medical name for the hole that is done in one's throat and allows, for example, to smoke a cigarrete without using your mouth. As seen in the last episode of the X-Files TV series.

Thanks in advance for any help, Ricardo M.

Tracheotomy. —Steve Summit (talk) 23:13, 21 March 2006 (UTC)

The irony is that that procedure is often needed as a result of throat cancer, caused by smoking. StuRat 23:21, 21 March 2006 (UTC)

Actually, tracheotomy is the name for the surgical procedure that creates the tracheostomy, the hole in the trachea. Brian G. Crawford 01:10, 22 March 2006 (UTC)

March 22

C++ to Java or Flash

Is there any way to convert C++ to a internet format without transliterating it manually? Assume that there is no IDE or complier to work with. --hello, i'm a member | talk to me! 00:24, 22 March 2006 (UTC)

This is a very strange question, sort of like "Is there any way to convert French to Shakespeare?". By "an internet format" I assume you mean a graphics/multimedia format which web browsers can natively display. And, furthermore, I'm guessing you're talking about a C++ program that outputs some graphics or animation, or otherwise does something visual which you're trying to capture.

If that is, in fact, what you're trying to do, there probably isn't a simple way of doing it. But if you can be a bit more clear on your situation we might be able to offer some suggestions. —Steve Summit (talk) 02:30, 22 March 2006 (UTC)

There's a open source tank game written in C++ that I want to put online that can load in a web browser. --hello, i'm a member | talk to me! 02:44, 22 March 2006 (UTC)

So you're trying to convert a program written in C++ to a program written in a web-based format. The short answer is no. The long answer is that it's generally possible to convert it to Java ('cause the languages have similar philosophies and syntaxes), but you'll need to do it by hand. And you'll need the Java compiler. (However, you can always just put up the existing C++ executable for people to download, but you've probably considered that.) --Geoffrey 03:28, 22 March 2006 (UTC)

It depends very much on what libraries the game uses. —Keenan Pepper 03:40, 22 March 2006 (UTC)

Firefox: SessionSaver

I use Firefox 1.5.0.1 with the SessionSaver extension, v. 0.2.1.031. To delete a session (under Tools > SessionSaver), you have to press the scroll wheel. But I use a laptop with no mouse -- just a touch pad and left and right buttons. When I try to use Ctrl + left click to simulate the scroll wheel (in Firefox, for nonusers, that opens the selected link in a new tab; this is ordinarily done with the scroll wheel), it doesn't always work (it might be a timing issue on my part). Is there another way to do this? --zenohockey 00:30, 22 March 2006 (UTC)

Holding Shift and left-clicking works. This site has more information. --Cadaeib 01:29, 22 March 2006 (UTC)

Perfect. Thanks! --zenohockey 05:12, 22 March 2006 (UTC)

End of the World

Can anyone provide me with a list of doomsday beliefs that put the date right around this year? I'd expect there to be quite a few of them, and I'd very much like to start Current Events in Government class each day with the announcement, "The world has not ended, and _____ apologizes for the mistake." Black Carrot 02:49, 22 March 2006 (UTC)

Most of the "prophets for profit" are smart enough not to give a specific date, that way nobody can ever prove them wrong. StuRat 03:28, 22 March 2006 (UTC)

Legend has it that Cardano (who wasn't dumb) predicted the date of his death exactly years before it happened. He commited suicide. Some people just hate being wrong. --BluePlatypus 04:42, 22 March 2006 (UTC)

Damn, that's hard core. But it isn't in the article... do you have a source? —Keenan Pepper 05:00, 22 March 2006 (UTC)

The prediction is mentioned, though. I read it here, in any case. (Worth reading in full, he was quite a character) --BluePlatypus 05:27, 22 March 2006 (UTC)

That is a very cool idea for a presentation :) It doesn't quite cover the very recent past, but you may want to browse through Timeline of unfulfilled Christian Prophecy. — QuantumEleven | (talk) 07:14, 22 March 2006 (UTC)

Sorry...Today is your last day.

Plant Fertilizer

I am aware that Nitrogen,Phosphoric Acid and Soluble Potash are all plant fertilizers, but they each have their own purpose. What is the benefit of each? Thank-You.--209.89.235.178 02:53, 22 March 2006 (UTC)

Since this is a double posting, I have forwarded Mac Davis's reply to the anon's question on their talk page. --Uthbrian (talk) 03:11, 22 March 2006 (UTC)

Planet Demoltion

After reading the Hitcher Hickers Guide to the Galaxy I sometimes think about the demolition of the Earth. What would be the cleanest and most efficent method for destroying the Earth? Patrick Kreidt

There's a whole Usenet newsgroup, alt.destroy.the.earth, devoted to this exact question. I haven't read it in years so I have no idea if it's all porn ads now. Anyway their nemesis was alt.pave.the.earth, the contributors to which were radically opposed to your project, because if you destroy the Earth, how are you going to pave it? --Trovatore 03:55, 22 March 2006 (UTC)

Lol, that's great. Here's the FAQ. —Keenan Pepper 03:59, 22 March 2006 (UTC)

It all depends on how thoroughly you want it destroyed. Is destroying all life enough, or do you want the physical ball of rock to be broken up as well? —Keenan Pepper 03:58, 22 March 2006 (UTC)

As our article on the Death Star notes, complete demolition of the Earth or a comparably-sized planet would require ridiculous amounts of energy; there is no known physically-plausible source (even technologically challenging ones like massive lumps of antimatter) for such energy output. As the article says, if you just want to destroy civilization, there are much easier and cheaper options - dropping a sufficiently large asteroid onto Earth, or, even cheaper, some cobalt-salted nuclear weapons. --Robert Merkel 04:35, 22 March 2006 (UTC)

Yes, a cobalt bomb is probably the most effective method to destroy civilization with current technology. With some advances in genetic engineering, however, a deadly virus might be more efficient. —Keenan Pepper 04:58, 22 March 2006 (UTC)

Cobalt bombs ar too salty for my taste. --Optichan 16:00, 22 March 2006 (UTC)

Haven't read the hitchhiker's guide, but it seems to me that the easiest way to destroy the earth would be to push it out of orbit, preferably into the sun, but into another planet would work. To completely stop the earth's movement around the sun, one would require 2.7X10^33 Joules. Then it would accelerate straight towards the sun (with minor bends towards other planets). Boom! No earth. For refence, if we were to store up all our energy that arrives on earth (primarily through solar radiation), we would have to wait about 4.9x10^8 years before we had enough energy to stop the planet. So it's a lot of power just to stop it. Of couse, I'm completely ignoring the fact that the forces on the earth that would be required to stop it would also rip it apart, but no matter. --AK7 17:08, 22 March 2006 (UTC)

Haven't read The Hitchhiker's Guide??!? You call yourself an educated, computer-using, sentient galactic being and you haven't read the seminal work in the field? Take a quick break and catch up on your reading, please, and come back when you've achieved a basic level of clutural literacy! :-) —Steve Summit (talk) 04:42, 23 March 2006 (UTC)

What if you stopped the moon from orbiting and let it crash into the earth? Less energy should be required, though what the result would be I don't know.Mark 17:40, 22 March 2006 (UTC)

Good point. The moon's KE relative to the earth is 3.8X10^18 joules, much much smaller than the earth's KE. It would take a very short time of accumulating power (days or shorter) before we could press the big red button. But I don' think the earth would be completely destroyed; there would certainly be plenty of debris which would clutter the area. Pushing it into the sun deals with this, although if shoemaker-levy 9 is any indication, it could have an interesting effect on the sun...--AK7 17:50, 22 March 2006 (UTC)

I have not done the math, but my suggestion was to devise a way to get all of the hydrogen in the oceans to undergo fusion. Don't know how that could be done, or how much energy it would yeild.

Well, if the destructor of Earth is a patient person then he/she could, instead of stopping the Moon in its orbit, slow the Moon's orbit. That would cause the Moon to spiral—slowly or quickly, depending on how much you slow the Moon—into Earth. This is fun! :D —OneofThem_(contribs) 20:37, 22 March 2006 (UTC)

What if, instead of stopping the Earth entirely (at utterly ruinous energy expenditure) we just adjusted its orbit? Kick it into a more elliptical orbit – maybe slingshot around Venus or something – and fling ourselves into the Sun that way? I'm not really keen to do the astrophysics for it, but I suspect we could save a good chunk of energy with that technique. Maybe save 50, 75%? TenOfAllTrades(talk) 04:18, 23 March 2006 (UTC)

A similar question was asked here in December. One reference I found useful was here. Dmharvey 22:00, 22 March 2006 (UTC)

Thanks all these suggestions have been increasingly amusing.

No science fiction apparatus is needed to destroy the earth. A single large enough nuclear bomb would suffice. There is no upper limit to the size of a hydrogen bomb. By simply cascading more fission/fusion stages in theory a device of any size can be constructed. Scientists have discussed a 50,000 megaton device which is probably relatively straightforward to make (for a superpower). There are 4.2E15 joules per megaton, so it would release 2.1E20 joules. The best possible yield-to-weight ratio is 166 kg nuclear material to megaton of output, so it would weigh 8300 metric tons, not exactly air-deliverable. Ironically Dr. Strangelove got it right: "Mr. President....When you merely wish to bury bombs, there is no limit to the size". Joema 05:26, 23 March 2006 (UTC)

Ah, but follow the math through from there. From our Death Star article, the floor on energy for destroying a planet seems to be at least 10 joules; some estimates run about a million times higher.

At 2E20 joules per 8300 tons, we get a minimum required mass of about 4E15 tons of hydrogen (even assuming a rather implausible 100% efficiency). Current global production of hydrogen is a paltry 5E7 tons per year, so we'd need to save our industrial output for a hundred million years to have enough.

The density of liquid hydrogen is about 70 kg/m, so we'd need about 5E16 m to store it. That's roughly 2000 times the volume of the Great Lakes, or – if my math is about right – about twice the volume of the entire Mediterranean Sea.

On the bright side, we do have enough hydrogen available on Earth. The hydrosphere contains about 1.4E18 tons of water, of which about 1.5E17 tons are hydrogen. So we'd only have to crack about 2.5% of all the water on Earth to make our bomb.

Note that the above estimates are based on the low end of the Death Star estimates and 100% efficiency. If the high end is correct, then the figures need to be a million times higher—and we don't have enough hydrogen. Pity. TenOfAllTrades(talk) 06:26, 23 March 2006 (UTC)

Digital rm to mp3 converter

Does anyone know any good freeware programmes that allow digital conversion from rm to mp3? -- Миборовский 05:06, 22 March 2006 (UTC)

First off, do you realize this will degrade the quality of the sound? Conversion from one lossy data compression format to another is never good. So, ask yourself if you really want to do this, and if so, you need something that can decode realaudio into an uncompressed format (e.g. WAV) and something that can encode that into an MP3 (like LAME). There's no way to convert directly from one format to the other. —Keenan Pepper 05:14, 22 March 2006 (UTC)

check here -- Mac Davis] ⌇☢ ญƛ. 06:34, 22 March 2006 (UTC)

Science/Environmental Science/Water/Rivers Concept or Theory Question

Hi, thanks for offering this service. My question might not have an answer, I'm trying to learn if there is a term for a theory that all water on the earth being some how being connected. Like how water form the ocean gets pulled into the air, then becomes cold and falls as snow on a mountain, then the snow melts and runs into a river that flows back into the ocean. I know this isn't scientifically how things work, but I was wondering if there was any informal or perhaps old mystical term that can be used to describe this idea of all water being connected or flowing. I am a poet and I'm exploring the idea of connectedness and thought I would see if there is any such term or concept. Thank you,

Schuyler

Are you looking for Water cycle or perhaps something more? Melchoir 05:23, 22 March 2006 (UTC)

Transistors

tell me the theory about insulated gate bipolar transistor and its functioning

This sounds like homework ... Our article on transistor might contain some useful stuff to get you started, though admittedly it could do with a bit of a cleanup. --Bth 11:39, 22 March 2006 (UTC)

Pollution rates

I have spoken to strong advocates of renewable energy, and most of them have said a significant decrease in air pollution would ensue if widespread use of them occurred. I was wondering if any of you know of any graphs/charts that would show projected air pollution rates now with the use of conventional energy sources vs. air pollution if alternative or renewable energy (i.e. ethanol, solar power, etc.) was used. Thanks -- Anonymous

Our articles on greenhouse gas, Global warming and carbon dioxide have some excellent graphs for pollution rates. Hope this helps. Kilo-Lima| 18:51, 22 March 2006 (UTC)

Note that some renewable forms of energy, such as burning wood, cause very high rates of air pollution, while some non-renewable sources, like nuclear fission reactors, have almost zero air pollution associated with them. Basically, anything you burn will cause air pollution, whether it's renewable or not, while most non-combustion based forms of energy have low air pollution associated with them. StuRat 19:06, 22 March 2006 (UTC)

It's also worth thinking about what you want to consider as 'air pollution'. Do you mean carbon dioxide alone? All greenhouse gases? Particulates (soot)? Oxides of nitrogen and sulphur?

From a CO₂ standpoint, biomass (mostly plant matter) is very 'clean', because when you regrow your supply of biomass you pull carbon dioxide back out of the air. (Burning the wood from a tree puts CO₂ into the air, which is pulled back out of the air when you grow a replacement tree.) On the other hand, if the wood isn't burned under carefully controlled conditions then you will generate a bunch of soot and smoke that may be undesirable. TenOfAllTrades(talk) 00:09, 23 March 2006 (UTC)

temperature and calorie burn.

First off, I recommend reading through this. Lots of fun, but the good stuff is at the bottom. Anyway, the basic idea is that the vast, vast majority of the calories we burn are radiated or conducted away from our bodies. And since our bodies will increase metabolism to stay at 98.6 F(37C), decreasing the temperature of the environment should help burn calories. I read somewhere that this is why we get lethargic in the afternoon; it's hot, we're not needing to burn many calories to stay warm, so our bodies slow down the consumption of glucose. I've also read from a couple different sources that shivering burns 400 calories an hour (on par with vigorous exercise) and this seems right since the whole point of shivering is to increase body temperature. Of course, to shiver, you have to cool yourself off considerably, and if you do it for more than an hour or two, you could get hypothermia.

That's obviously a problem. Hypothermia sucks, plus it can kill you when your body temperature drops once your cells run out of energy stores (stored in glucose or glycogen). Which is where part 2 of my future-fad-diet comes in: Caffeine. Stimulates lipolysis and dramatically increases glucose in the bloodstream, which should help keep you from dying of the hypothermia. On the negative side, it reduces the amount of blood near the skin, which means that you won't radiate heat so well. Oh well, it's an acceptable loss. Oh, and just for kicks, caffeine is a diuretic; assuming you're drinking ice-cold water, this will help you burn an extra few calories since every liter of ice water you drink has to rise to 37C before leaving your body. It's only 37 kilocalories a liter, but it's something.

So the fad diet would go something like this. Get pure caffeine (thank you eBay). Put 500mg in an absolutely bitter-tasting concoction. Drink it during the early evening. Stay up all night, nude or mostly so, in a cold room, and take a shower (doesn't have to be cold, just don't make it hot) and don't dry the water if you can stand it. All that evaporation will draw away heat from the skin, and you'll shiver away fat all night while you write about it on Misplaced Pages (actually, you'll write about it later on wikipedia after finding the research on it in google answers the night of). It's the Next Big Thing!

So, the question. I'm pretty much just wondering if there are any glaring problems in this (besides the obvious ones of killing people who overdo it and freeze themselves to death). Plus the google answers page says "expires 3-25" and I'm not sure if it's going to just dissapear then. In any case I'd like to produce some sort of record for other lazy overweight teenagers like myself who avoid exercise at all costs to look through. Until them scientists perfect diet pills that don't result in death, this may be the only way to lose weight while not leaving our precious computers.

Oh, and another crazy/dangerous idea: exercise through electric shocks. The major risk is, of course, if your device malfunctions, you're a dead man... but mucles tense in the presense of an electric current, no? So by regularly applying and un-applying an electric current (say at 1 or 2 Hz), could we get some fair exercise for muscles? The next logical step is to make it so that this happens when one is hurt in a game. It takes a rumble pack to a whole new level. --AK7 18:40, 22 March 2006 (UTC)

Well, those methods sound like typical fad diets, in that they are unhealthy and less effective than the proper advice to "eat healthy food, consume fewer calories, and exercise". Specific problems:

• Cold puts a stress on the immune system, making the subjects more vulnerable to disease.

• Any method that causes you to burn more calories will just make you hungrier, too. So you will eat as many calories as you burn, and then some.

• The more calories you burn, the more free radicals are released. The aging effect of those can be reduced by anti-oxidants, but not eliminated.

• Caffeine has a number of health problems associated with it.

• Electro-shock is dangerous, and has also already been marketed (briefly, I assume due to lawsuits) for strengthening facial muscles. The only legit use of this method I see is to keep the muscles of comatose patients in shape.

StuRat 18:57, 22 March 2006 (UTC)

I've seen ads for muscle stimulators for abdominal muscles so you don't need situps. Don't know if they take more time than situps. Plus , it must be very annoying.

For typical person, basal metabolic rate is 40 watts == 825 kcal/day. That is , if you lie in bed all day, you still use 825 kcal. If you move around, than they typically say, typical person uses 2000-2500kcal/day. If you're an Olympica athelete in training, you might eat and use 6000kcal/day (according to what I read). If you want to lose weight, just reduce intake below usage. (obviously) Energy is stored in different ways in the body, long term storage is fat. To "burn" fat most effectively, use long (more than 1/2 hour) aerobic exercise, that's what stimulates fat utilization. Plus you'll be more buffed than if you lie in bed and eat only 400kcal/day. I suggest, a bicycle and an MP3 player/FM radio with headphones, and a few cups of coffee before starting out. It's fun. (Ignore all fads, dietary, philosophical, political.) GangofOne 21:58, 22 March 2006 (UTC)

Caffeine is already found in most diet pills. 500mg is a monstrous amount of caffeine to take in one dose, as a can of Coke has 40mg of caffeine in it. An overdose of a stimulant like caffeine can cause heart arrythmia and extreme anxiety. As for lowering the room temperature, I knew people in college in New Hampshire who would keep their house at 50 degrees (Fahrenheit) to keep weight off. According to them, it worked. Hypothermia is a dangerous medical condition and should never be induced outside of an operating room. Brian G. Crawford, the so-called "Nancy Grace of AfD" 01:33, 23 March 2006 (UTC)

Of course, I also knew wrestlers in college who would jog around in black plastic garbage bags and then cool down by going to the sauna for an hour, also to keep their weight off. I guess what all these ideas have in common is that you have to be utterly deranged to subject your body to such risk for the sake of a few pounds. ~Mary

Nuclear Bomb

Is it possible to make a non-radioactive nuclear bomb, or something as stong as a nuclear bomb without the radioactivity?

For example, the Hiroshima bomb was the equivalent of 13 kilotons of TNT. How about 13 kilotons of TNT? Are there more design specifications you wish to mention? GangofOne 20:45, 22 March 2006 (UTC)

If you don't have a size limit, then yes. The power of nuclear weapons is measured in kilotons or megatons of TNT, so, by definition, thousands or millions of tons of TNT would have the same explosive force. If you want it to be as small as a nuclear weapon, then we would need some future technology, say an antimatter bomb, which should actually be over 10,000 times more powerful given an equal weight of antimatter versus uranium or plutonium. StuRat 20:54, 22 March 2006 (UTC)

• Actually, it's not completely obvious that you could simulate the blast of a big nuclear weapon by stacking millions of tons of TNT or other conventional explosive. Your bomb would be the size of a large building and you would need to make sure that all parts of the explosive actually contribute to the blast without being destroyed first. I imagine pyrotechnics experts could deal with that by using many detonators and suitable control circuits, but I'm not one and I don't know. Another points is that there clearly wouldn't be any single place that would get the equivalent of the extreme blast forces very close to the nuke, although at say a half-mile from the center or further out, you might not be able to tell the difference. --Anonymous, 22:40 UTC, March 22, 2006.

I understand that the larger the volume of the explosive, the less damping effect distance has. E.g, a 1MT nuke may expend a lot of energy in its immediate vicinity, but the larger volume of a 1MT TNT bomb will expand much further, projecting force much further away. The principle behind FAEs is similiar, in that you don't need quite as much explosives to do damage over a larger area. Tzarius 07:41, 24 March 2006 (UTC)

This has already been done. FAE (Fuel Air Explosive) bombs exist that are .02 Megatons, that is about 20 Kilotons.

Bullshit. Pardon my french, but the biggest Thermobaric weapons are still only in the tens of tons. .02 Kilotons, not .02 megatons. However, some of the smallest nuclear weapons have warheads that can make a blast as small as tens of tons. You should keep in mind, though, that a small nuclear weapon unleashes blast effects in a way very different from a larger weapon, since most of the ionizing radiation impacts the target directly, rather than being converted to a blast wave and overpressure through atmospheric heating. A Davy Crockett nuclear weapon will be more likely to fry you with radiation than blast you apart, especially if you're inside a tank. Night Gyr 22:21, 22 March 2006 (UTC)

My source told me it was .02 MT, but I am entirely willing to believe he may have misstated. It is true, though that FAE devices have yeilds approaching Nuclear Devices.

Please note that a "ton of TNT" or "kiloton of TNT" is a unit of measure, and does not directly correspond to a certain weight or mass of TNT. Johntex 23:29, 22 March 2006 (UTC)

Interesting. I certainly think it was intended to correspond with the weight, but I suppose variations in the explosive power of TNT and it's weight might throw it off a bit. This reminds me of "horsepower", which seems to be considerably less than the power of a typical horse. A small car, for example, might have an anemic 50 HP engine and have rather slow acceleration. However, if you could hook that same car up to 50 actual horses, I would expect to get quite impressive acceleration. StuRat 23:50, 22 March 2006 (UTC)

The original bombs were calibrated against test detonations of TNT, to give some sense of scale, so you're not wrong. However I imagine that one can really change things around with how you detonate TNT to get different types of effects, which is why they eventually developed a "ton of TNT equivalent" as a fixed expression of just energy. --Fastfission 01:48, 23 March 2006 (UTC)

In theory, yes. A hydrogen-hydrogen or deuterium-deuterium fusion bomb, without a fission detonator, would have no radioactive fallout. The problem is finding a replacement for that detonator: there's nothing else known that can produce the combination of pressure and temperature needed. --Serie 00:29, 23 March 2006 (UTC)

Wouldn't subatomic particles coming from the deuterium convert some elements they strike into radioactive isotopes ? StuRat 00:39, 23 March 2006 (UTC)

You'd probably generate a lot of neutrons and from that some artificial radioactivity, as I understand it. But you would lack fission products which make up a lot of the really nasty stuff that comes out of a bomb. We have an article on pure fusion weapons for those who are interested. --Fastfission 01:48, 23 March 2006 (UTC)

• You can accomplish the same damage as a "nominal" nuclear weapon easily with conventional weapons. The firebombings of Tokyo destroyed more area and killed more people than the bomb of Hiroshima. The difference is that the former case took a few hundred bombers each loaded to the brim with tons of explosives, while the latter took one bomber with one bomb. There's an economics of scale there, if you are interested in just destroying things. --Fastfission 01:48, 23 March 2006 (UTC)

• Oh hey, dig this article I just stumbled across while trying to look up the "Minor Scale" non-nuclear nuclear simulation (which I had just remembered): List of the largest artificial non-nuclear explosions. --Fastfission 01:52, 23 March 2006 (UTC)

A Nap

Whenever I take a nap during the day, I will wake up feeling light-headed and have a bad taste in my mouth. I will continue feeling so for about 30 minutes afterwards. Is there any way to keep this from happening? — Ilyanep (Talk) 23:55, 22 March 2006 (UTC)

I find that after a nap you end up with something very similar to morning breath. The light-headedness is pretty common as far as I know. It's usually your position and the blood rushing through your head (sometimes you can see it as points of light and darkness during the dizziness). As for a cure or a preventative? I don't know if there is any. Keep a mint or some minty dental floss around and chew on that to cure the breath. The dizziness can be lessened by standing up slower. M@$+@ Ju ~ ♠ 00:05, 23 March 2006 (UTC)

Hmm...well the thing is that I start feeling lightheaded before I even sit up or stand up. — Ilyanep (Talk) 00:44, 23 March 2006 (UTC)

I think part of it is also caused by a combination of dehydration and congestion - if your nose is blocked you breathe through your mouth, which dries out. I haven't found a decent cure for it myself, sadly enough. Confusing Manifestation 00:11, 23 March 2006 (UTC)

As for the dizziness, try sitting up for a couple minutes before you stand up. The bad taste could also be a minor case of acid reflux disease, which is typically worse when lying down. Try chewing some antacids before your nap, that might lessen the effect. StuRat 00:31, 23 March 2006 (UTC)

Acid reflux appearing at 14? — Ilyanep (Talk) 00:44, 23 March 2006 (UTC)

It's possible. Do you having a burning or sore feeling in your throat or mouth ? StuRat 01:00, 23 March 2006 (UTC)

Not really...it's really only a bad taste. And brushing my teeth gets rid of it. — Ilyanep (Talk) 02:20, 23 March 2006 (UTC)

In that case the cause might be a lack of air circulating through your mouth when you sleep (assuming you breathe through your nose). This lack of ventilation allows odors and tastes (from decomposition of food) that would otherwise be ventilated, to accumulate. You might also try brushing your teeth before each nap. StuRat 09:57, 23 March 2006 (UTC)

Galaxies

What is a common feature among galaxies?

They all contain students who expect others to do their homework for them. StuRat 01:22, 23 March 2006 (UTC)

I wish you'd think. Click on the word "galaxy" now in your question. If you haven't discovered that many galaxies in outer space including our own feature stars. Because God lives in heaven, which is in the sky, in the clouds, galaxies are all higher than God. Galaxies all have the letter q in their middle name. I hyperlinked the word "galaxies" to a Misplaced Pages article about galaxies. It took me a while to learn wikipedia's programming language, and on the way, one of the first things I learned was how to link words to Misplaced Pages articles. I learned this many years ago. It was spring 2001 and the muggy amazon air was wearing heavy in my lungs and covered my body with a cloak of sweat. It was getting dark and I knew my Kogi tribal guide was trembling with fear and wouldn't help me for long as we near the hidden temple. -- Mac Davis] ⌇☢ ญƛ. 08:37, 23 March 2006 (UTC)

Weird question! They must have dozens of common features i.e those features that are common to galaxies!! They are all spiral, elliptical or irregular. Each has on average 100,000,000,000 stars (roughly). They are all made up of stars (and gas and debris). They all can't be seen with the naked eye (except Andromeda and one other). They rotate. The spirals have spiral arms but the ellipticals don't. They are all travelling ever so fast through space. They like to to clump together into groups of galaxies. I wrote all this from memory without reading the article so you can check me out then invent other similarities for yourself (note: I am not an astronomer) - Adrian Pingstone 20:50, 23 March 2006 (UTC)

Methamphetamine Production - Odorous or not?

Does the illegal "cooking" of Methamphetamine cause a noticeable or describable odor or scent?

What does it smell like? Is the smell a strong, pervasive odor or a vague, indistinct fragrance?

There are several different synthetic pathways that can be used, each with its own associated smells. See Methamphetamine#Production. —Keenan Pepper 06:14, 23 March 2006 (UTC)

(PDF) lists ether-like, solvent-like, vinegar-like, and ammonia-like odors among the possible smells of a clandestine meth lab. Are you wondering if your neighbors are running a meth lab? Are you planning to set one up yourself? In either case be advised that possible meth lab odors may be probable cause for a search. —Charles P._(Mirv) 06:26, 23 March 2006 (UTC)

The odors also tend to be toxic and explosive, so I would call the police and evacuate, if you suspect a meth lab. StuRat 09:51, 23 March 2006 (UTC)

As someone whose occupation involves carrying out organic chemical reactions much like those associated with "cooking" methamphetamines, I can say that the odors associated with it are definitely noticeable and in most cases very distinctive; the fumes are also often toxic and highly flammable. There is very little chance that anyone could get away with it for long without being noticed unless they are quite isolated from neighbors. Organic chemists work in fume hoods that carry solvent and other chemical vapor away from them; otherwise it would be too dangerous (and unpleasant) to be exposed to them. --Ed (Edgar181) 12:46, 23 March 2006 (UTC)

Impact on Rotation

Has the combined effect of all human and animal activities since life began on Earth had any appreciable impact on the rotation of the Earth? JackofOz 04:12, 23 March 2006 (UTC)

I once heard, from someone in a position to know, that the mass of water held at elevation behind dams had increased the earth's angular moment of inertia and therefore, ever so slightly (but measurably) decreased its rotational speed, in the manner of a skater extending their arms. But I'm not sure I believe it. —Steve Summit (talk) 04:35, 23 March 2006 (UTC)

No. Have you been to that dumb "jump" site? -- Mac Davis] ⌇☢ ญƛ. 04:58, 23 March 2006 (UTC)

No, what's the url? --GangofOne 01:19, 24 March 2006 (UTC)

World Jump Day EricR 02:01, 24 March 2006 (UTC)

See the Polar motion article. If you beleive humans are contributing to melting of the Greenland ice sheet then, yes. EricR 04:59, 23 March 2006 (UTC)

And, if you believe its melting ;) -- Mac Davis] ⌇☢ ญƛ. 08:21, 23 March 2006 (UTC)

Bearing in mind the inclusion of the word "appreciable", I would say no. Any changes brought about by life on Earth are completely insignificant. StuRat 09:48, 23 March 2006 (UTC)

Polar motion is significant for those trying to accurately measure positions on the earth's surface. The contribution of isostatic rebound seems to be "appreciable", as in possible to estimate, measure or perceive. Whether or not humans have had an appreciable impact on off-axis glacial melt depends on who you ask i guess. EricR 17:54, 23 March 2006 (UTC)

According to Resnick and Halliday, Physics 3rd ed, 1977, p11, cites Essen Physics Today July 1970, shows annual variation in Earth's rotation of 160 parts out of 10, and decreasing every year. (Cesium clocks in use then are good for 1 part in 10.) Explanations mentioned: tidal friction between water and land. Seasonal motion of the winds. Melting and refreezing of polar icecaps. Something I read somewhere else: deciduous trees losing/regrowing their leaves seasonally. Have no doubt that the comings-and-goings of HuMan have an effect, but it will never so great as the tides and flows of nonhuman nature. GangofOne 01:06, 24 March 2006 (UTC)

Graphs - all pairs shortest path

Many of the APSP algorithms highlighted specify that they are for directed graphs. eg. the Floyd-Warshall algorithm. Can they also be used on undirected (all edges positively weighted) graphs?

Yes. Transforming an undirected graph into an equivalent directed graph is very easy, if you think about it. With an appropriate data structure implementation the algorithm doesn't even have to care whether the graph is directed or undirected. 130.188.8.13 09:51, 23 March 2006 (UTC)

Many thanks for the help.

DNA to organism

Say someone works out the complete DNA sequence (including mitochondrial DNA and whatever else) for some organism, for example a wombat. You've given a CD-ROM of the sequence but not told what the organism is (maybe you're told it's a mammal). Of course maybe you could match it against some database but let's not count that. Is it possible in principle to run the DNA sequence through a computer program and simulate the growth of the organism to the point that you can figure out what it looked like? Obviously nobody knows how to do this today, but is it plausible? What kind of knowledge and technology needs to be developed for it to happen? Thanks. Phr 13:21, 23 March 2006 (UTC)

I'd say that it isn't plausible. That would basically assume that the environment (womb) that the thing grows in is of no great significance to the result, which it is. --BluePlatypus 13:40, 23 March 2006 (UTC)

One of the big challenges would be in figuring out how to convert a DNA gene sequence into a fully folded three-dimensional protein. Proteins are synthesized as long chains of amino acid residues; these chains are folded into complex shapes to give them their final structure and function. Modelling this process is extremely difficult, and we aren't anywhere near being able to do it yet.

Of course, once you fold those proteins, you then have to model how they interact with other complex molecules in their surroundings—particularly other proteins. Also nontrivial, given the number and variety of different molecular species in a cell. TenOfAllTrades(talk) 13:57, 23 March 2006 (UTC)

There is a big gap in our current knowledge about how to get from genotype to phenotype in a complete organism; "development" is still a big question mark a majority of the time (the number of places in which we understand clearly how one gets from DNA to a given phenotype is dashingly small in comparison with the amount of DNA an entire organism uses). In any case, one would probably have more efficient ways to figure out what sort of animal any piece of DNA was than trying to model the whole organism -- certain genes are likely to only be present in mammals, for example, and you could just look for those if that's what you want to know. --Fastfission 14:26, 23 March 2006 (UTC)

Since he seemed to be asking "would it ever be plausible", not, "is it plausible today", I would say yes, given maybe a century of new discoveries, we could do all of that. I agree with Fastfission that it would hardly be the most efficient mechanism for identifying a strand of DNA, however. StuRat 17:53, 23 March 2006 (UTC)

Even if it were technically possible (which I highly doubt) to model a whole organism at the level of detail required, I don't see how any discovery or technology would provide information that simply isn't there; DNA alone just does not suffice to grow a complex organism. You could guess at the environmental factors, and work by trial-and-error, but that would always just be a guess which you wouldn't be able to verify. --BluePlatypus 00:03, 24 March 2006 (UTC)

Yeah, I meant was it possible even in principle. I was imagining two kinds of applications: 1) You get hold of some dinosaur DNA and you want to know what dinosaurs really looked like, and it's much more appealing to just drop the DNA sample into a sequencing machine and get a nice dinosaur picture on your computer a few minutes later, than spend years doing some Jurassic Park process of growing an actual dinosaur and ending up with a huge dangerous beast clomping around eating your lab assistants. 2) You want to genetically engineer a flying wombat, so you sequence the DNA of a regular wombat and model the effects of different possible gene splices on your computer til you get what looks like flight capabability. Again, this is much faster and less messy than waiting through a whole wombat gestation cycle for each splice that you want to test. Anyway, the answers given are very informative. Thanks again. Phr 02:33, 24 March 2006 (UTC)

Thanks, everyone. The quality of answers found on this page, not just to this question but to most of the others that I've looked at, is absolutely astonishing. What an amazing resource this is. Phr 22:14, 23 March 2006 (UTC)

Finding Easter Eggs

How easter eggs (hidden inside any software) can be found? Whether it is possible or not? If possible then how? Is their any tools (softwares) for this?

Poeple who find these things (rather than getting inside tips) spend hours or days trying every combination of keystrokes and everything, in the hope of the fame and riches that come from finding easter eggs. Automation would not be possible. Notinasnaid 15:23, 23 March 2006 (UTC)

"Fame and riches"? That's a joke, right? I think some keystroke automation might be possible, but I'm not sure. I suspect nearly all easer eggs are leaked from inside the team that made the software. Johntex\ 15:34, 23 March 2006 (UTC)

In many cases it can be done by looking at the code, and searching for things that look odd. For great justice. 16:36, 23 March 2006 (UTC)

Another way which seems to work is looking on google for sites which list easter eggs and cookies :) Grutness...wha? 00:56, 24 March 2006 (UTC)

The Easter egg (virtual) article might give you the information you want. --Halcatalyst 03:34, 24 March 2006 (UTC)

• A Debugger program can look inside the code and see what variables are being used, then you can change these variables and see what happens. A GameShark type device does this on consoles, but it can be done in software too, and then it's just a matter of finding the corresponding code to trigger it inside the program. Night Gyr 18:26, 24 March 2006 (UTC)
  • Which is a bit more difficult than it may sound. --Optichan 18:34, 24 March 2006 (UTC)

explorer

Suppose for a second that for whatever reason you've been using IE as a browser (why? who knows, sadism? bored? whatever..) and your browser freezes, why the hell is it that iexplorer.exe itself, the program that is actually freezing, never crashes per se, but rather explorer.exe is always the one that crashes, I mean right now, explorer is totally dead, yet I'm using iexplorer to type this question, even though I have no access to windows itself as explorer is quite dead, why does one crash, but not the other?--64.12.116.74 17:23, 23 March 2006 (UTC)

One problem that can cause this is memory overflow. If one application allocates a 100 Kb block for writing data, then proceeds to write 150 Kb of data to that block, the extra 50 Kb will overwrite whatever was in the next memory location. This could be the same application, another application in the same suite, or a completely unrelated application, even the operating system. These type of "memory leaks" can be extremely difficult to locate, as the source is not immediately apparent. If properly designed, an operating system would not permit any application to write to memory it has not explicitly allocated. However, the common operating systems have no such protection. StuRat 17:46, 23 March 2006 (UTC)

Um, no, all recent versions of Microsoft Windows have memory protection, which means a program can only screw up its own data. If it tries to access the memory of a different process it will crash with a segmentation fault (aka "General Protection Fault"?). A memory leak is a different thing, when a program keeps allocating memory but not freeing it, so the memory cannot be reclaimed by the OS. —Keenan Pepper 17:58, 23 March 2006 (UTC)

How recently ? My (admittedly old) computer doesn't have this feature, and I'm guessing the person who asked the question doesn't have this feature either. StuRat 18:43, 23 March 2006 (UTC)

I don't know much about Windows, but Microsoft Windows 3.0 said it had memory protection. —Keenan Pepper 00:50, 24 March 2006 (UTC)

Which doesn't really make it so. Windows NT/XP/2000 has true memory protection, in the sense that it catches any and all such overstepping of bounds. Windows 95/98/ME did not really have memory protection in that sense, although it did have safeguards in place to stop programs from writing to obviously wrong places (like memory address 0), which Microsoft touted as "memory protection". --BluePlatypus 13:20, 24 March 2006 (UTC)

There's a much more likely problem here. explorer.exe uses Internet Explorer (iexplore.exe) to display many of the things it displays. For example, when you press F5 in folder view, notice how it refreshes the folder view? That's because F5 refreshes the page in Internet Explorer, and Windows Explorer uses certain iexplore components. So when iexplore.exe crashes, explorer.exe likes to crash as well, since it depends on parts of iexplore to run. -- Daverocks (talk) 08:07, 24 March 2006 (UTC)

Tension Tensor, Forces...

You're given a tension tensor:

${\displaystyle {\begin{pmatrix}0&x_{3}&0\\x_{3}&0&-x_{1}\\0&-x_{1}&0\end{pmatrix}}\,}$

If there are no volume forces, how can I prove this fluid is in balance? How can I calculate overall surface forežce that acts on the upper part of the sphere ${\displaystyle x_{1}^{2}+x_{2}^{2}+x_{3}^{3}\leq 81\,}$

Is this a homework problem? If so, you should do your own homework. If not, I haven't a clue.  :-) Johntex\ 20:30, 23 March 2006 (UTC)

No, it's not. It's just a problem and I don't have a clue how to solve it.

This looks like a matrix. Would using matrix arithmetic help? --Halcatalyst 03:06, 24 March 2006 (UTC)

Tensors are represented with matrices. You have to know at least the basics of matrix arithmetic, yes. But that's not the problem here.

If by tension you mean force, then there is no such thing as a tension tensor. You must be meaning stress tensor. In that case, the equilibrium ("balance") is given by:

${\displaystyle {\frac {\partial {\sigma _{11}}}{\partial {x_{1}}}}+{\frac {\partial {\sigma _{21}}}{\partial {x_{2}}}}+{\frac {\partial {\sigma _{31}}}{\partial {x_{3}}}}+b_{1}=0}$
${\displaystyle {\frac {\partial {\sigma _{12}}}{\partial {x_{1}}}}+{\frac {\partial {\sigma _{22}}}{\partial {x_{2}}}}+{\frac {\partial {\sigma _{32}}}{\partial {x_{3}}}}+b_{2}=0}$
${\displaystyle {\frac {\partial {\sigma _{13}}}{\partial {x_{1}}}}+{\frac {\partial {\sigma _{23}}}{\partial {x_{2}}}}+{\frac {\partial {\sigma _{33}}}{\partial {x_{3}}}}+b_{3}=0}$

${\displaystyle \sigma _{ij}}$ are the components of your tensor. In your case, there's no body force ("volume force"), so b₁ , b₂ , and b₃ are zero. It's very easy to apply these conditions in your case, and find the answer. Hope this helps! deeptrivia (talk) 01:21, 25 March 2006 (UTC)

For the second part, you can use Cauchy's principle (will create article soon) to find out the net force on the top surface of the cylinder. The principle states that the traction on a surface element whose area normal is defined by ${\displaystyle n=^{T}}$ is given by the vector ${\displaystyle \sigma n}$. You will have to consider an infinitesimal area element of the surface and find its area normal (convert to spherical coordinates, and this should be a cakewalk), and integrate over the top surface. There might be some intuitive arguments (symmetry, etc.) which could be used to avoid this integration, but this general procedure is extremely straightforward too. deeptrivia (talk) 01:40, 25 March 2006 (UTC)

Apollo missions & orbital mechanics

I have a question about a technical aspect of the Apollo missions. From my understanding, the ship would launch, go through staging of the first and second stages, orbit the Earth, go through a systems checkout and then initiate the trans-lunar injection (TLI) burn which would take the ship out of Earth orbit and send it towards the moon at some high rate of speed.

During the TLI, the CSM would detach from the 3rd stage, rotate and maneuver in order to dock with the Lunar Module. The CSM would extract the LM from the 3rd stage and then use its thrusters to separate from the 3rd stage. The 3rd stage would then be sent to crash into the moon.

The thing I don't understand is this: how was the CSM able to travel backwards towards the 3rd stage while still speeding towards the moon? I know that once you start talking about vacuums, space and zero-gravity that all the things that usually make sense go out the window, but I just can't get my head around the fact that ostensibly it's a vehicle that manages to continue travelling east while at the same time heading west. It's like being on a train that's heading east and walking west down the car. But what is the force that represents the train?

My only guess is that it's something to do with gravity: does the TLI merely change the shape of the orbit of the CSM such that it is elongated enough to take the CSM to the point where the lunar gravity takes over?

Did I just answer my own question?

Rotational velocity is differnt from linear velocity. Imagine a car that "spins out" on a wet road. The car starts out traveling east, goes into a spin, and is now facing west, but overall, the car is still traveling east. The low friction of the wet road makes this easier. In space, with zero friction (ignoring space dust) this is even easier. Johntex\ 20:29, 23 March 2006 (UTC)

If I understand you correctly, it's just the case of both objects moving in direction X, but with different velocities, and by changing the relative velocities of each object they can converge or separate as they please.--inks 20:56, 23 March 2006 (UTC)

Ahh -- so it's not so much that the CSM would actually start travelling towards stage 3 so much as it would slow down slightly such that stage 3 would meet up with it. I imagine that at the speeds at which they were travelling such minor adjustments to their velocity would have little overall effect.... Thanks!Xous 22:23, 23 March 2006 (UTC)

That's right, from the frame of reference of Earth. From the frame of reference of the either the CSM or LM you would describe it differently, but I don't want to confuse you more by going into that. StuRat 22:36, 23 March 2006 (UTC)

It's worth noting that the separation of the CSM from stage three was not accomplished by the main propulsion engine of the CSM (doing that would fry the LEM). It was done with reaction control engines placed at four places around the circumference of the service module. These engines had small jets pointing in several directions and allowed for the turning of the CSM to face the LEM and also for the slight thrust necessary to slow the CSM down relative to the third stage and LEM. They were also used to "reverse the LEM out of the garage" of the third stage. Only once the craft was clear of the then obsolete third stage were the main engines fired. The same jets were used to jettison the service module from the command module prior to earth re-entry. Grutness...wha? 01:04, 24 March 2006 (UTC)

RSS program

Is there any RSS program which download main page of a particular web-sites? roscoe_x 20:36, 23 March 2006 (UTC)

Um, could you clarify your question further? RSS is live feeds, which update frequently. Downloading the main page of a particular website is as simple as pointing your web browser to its URL. -- Daverocks (talk) 07:50, 24 March 2006 (UTC)

Also, you might want to check out our article on RSS (file format). -- Daverocks (talk) 07:52, 24 March 2006 (UTC)

Making a homepage with RSS feeds, Gmail, Yahoo Calander, etc

I want to make a one-stop home page for myself which includes things like my Gmail inbox, my calander, my Remember The Milk to-do list, RSS feeds, recent Flikr pics and so on. Is (any of) this possible, and what kinds of tools exist for such a page?

Any advice greatly appreciated, Thanks, ~Mary

Have you tried personalising your Google homepage? There are modules for displaying your Gmail inbox, event calendar (although not Yahoo! calendar), to-do list, flickr feeds and any RSS feed (click Add Content in the top left and paste the URL into the text field under 'Create a Section'). Bewildebeast 12:45, 24 March 2006 (UTC)

Wow, thanks!

computer internal hard drive

Is it possible to use Windows Explorer to divide my internal hard drive so that there is a new drive to then create 26 new files labled A-Z? My plan is to install a scanner to copy each subject's information and save this to that file (in the new drive, for example, drive G) for quicker subject reference.

My goal is to eventually do away with "paper" files and have the files on the hard drive.

I appreciate any information you may give.

Sincerely,

--205.188.116.74 21:42, 23 March 2006 (UTC)

Why would this be any faster or easier than just having 26 folders labled A-Z in your C: drive? It seems rather that it would be unnecessarily complicated — it would be more difficult to transfer documents, or do global changes on your file set, not to mention that it would just require an extra step of navigating to each partition. Anyway, in answer to your question, there are a number of utilities listed at Partition (computing). — Asbestos | Talk (RFC) 21:49, 23 March 2006 (UTC)

Also, Windows Explorer cannot alter drive partitions, which is what you are asking to do. Also also, putting 26 partitions on a single drive will waste a lot of the drive. Not only do you need overhead for each partition, you have to hard-set the partition size when you make it. How much bigger should the S partition be than the X partition? --Kainaw 23:27, 23 March 2006 (UTC)

The easiest idea is not to remember approximately where you stored some information, but to find it quickly. Try Copernic or Google, they have home research utilities to index your data on your drive and find them from any word(s). --DLL 17:34, 24 March 2006 (UTC)

Chemistry help

I've been trying to work this problem out, but I'm hopelessly stuck. Could someone explain to me how to do this?

50.0 Liters of hydrogen gas and some oxygen gas mix to form water. Calculate the volume of oxygen needed to completely use up the hydrogen. What mass of water forms? (The reaction is kept at STP).

I have no idea what to do unless I can convert Liters to grams...please help.

This sounds like a homework problem. Hint: the problem tests your knowledge of Avogadro's law, part of the ideal gas law. Phr 22:09, 23 March 2006 (UTC)

The formula for water is H2O. So you need half a many atoms of Oxygen as Hydrogen to make water. Find the number of atoms of Hydrogen in 50.0 Liters. Take half that number and find the volume of Oxygen. Find out the mass of the number of Hydrogen atoms and the mass of the number of Oxygen atoms and add them together. You do not really need to calculate the actual number of atoms, just know that 6.02 * 10^23 atoms is equal to the atomic weight in grams This is called one Mole. From the

density of Hydrogen you can find out the mass of 50.0 Liters and thus how many Moles it is. Take half that number of Moles and find the mass of Oxygen. Now using the density of Oxygen you can find how many Liters that is.

Thank you! But how do I find the number of atoms in Liters?

You make the not-unreasonable assumption that the gasses are ideal and use the ideal gas law to calculate the number of moles of H₂ in 50L. You then work out how many moles of O₂ are used in the reaction which gives you the volume of Oxygen needed. You also know how many moles of H₂O are created from the reaction, which together with the molar mass of water gives you the mass of water formed. -- AJR | Talk 00:50, 24 March 2006 (UTC)

So is it safe to assume taht 2.23 moles of hydrogen is about 2.23 grams since H has 1 gfm?

2.23 moles of hydrogen atoms, yes. But Avogadro's law is about the volume in liters per mole of gas molecules. Remember that hydrogen molecules at STP are H₂ (splitting them apart takes a tremendous amount of heat), so each hydrogen molecule has two hydrogen atoms. It's the same way with oxygen molecules. Anyway, I think the point of the exercise is to understand how to use Avogadro's law, so please click on the link and see if it explains what you need. Phr 02:17, 24 March 2006 (UTC)

Right. Thanks!

You are all missing the easiest solution, which is to use Gay-Lussac's Law directly. Volume ratio equals mole ratio, hence half of 50 = 25 litres. Then, for the mass of water, moles hydrogen = moles water = 50/22.4. The molar volume of hydrogen (and any other gas]] at s.t.p. = 22.4 litres. Then simply multiply by 18 to get the mass of water formed.G N Frykman 19:47, 24 March 2006 (UTC)

MicroATX motherboards

I'm thinking of getting a MicroATX board to save £20 compared to a similarly-featured ATX board. Could I install a MicroATX motherboard in my ATX case? Also, is it wise to get a MicroATX board just because it's cheaper? Is there anything I'd be missing out on (other than fewer PCI slots)? Thanks. Sum0 22:36, 23 March 2006 (UTC)

Well, the ATX article says A full size ATX board is 12" wide by 9.6" deep (305 mm x 244 mm). This allows many ATX form factor chassis to accept microATX boards as well. And the MicroATX article says MicroATX towers are a lot smaller than typical ATX towers. This means that although the same standard hardware is supported, it is supported in lower quantities. So you can install one, but you may not be able to shove as much hardware in there. Perhaps you should check one out to be sure that you can fit all the components you want in there. --Optichan 14:44, 24 March 2006 (UTC)

Airport Extreme Compatability

Will my Netgear Wirless router with wireless g format work with airport extreme, or do I have to Buy anything? Seamus215 22:53, 23 March 2006 (UTC)

I'm assuming you have a Mac with an Airport Extreme card, yes? They will work very well together.

Yup, Airport Extreme and wireless 802.11g are completely compatible. Sum0 09:31, 24 March 2006 (UTC)

March 24

the moon

Why is our moon the only one in the universe without a name?

It has a name, Luna. There just isn't much call to use it's name, since everyone knows which moon you're talking about when you say "the moon". StuRat 01:22, 24 March 2006 (UTC)

• There are billions of moons in the universe that humans haven't given names to, because humans have not yet discovered them. It's only the tiny, infinitesimal proportion of moons that exist in our Solar System that have ever been named.

• Our Moon has different names in different languages. Luna is its name in Latin, Russian and some other languages. It's "der Mond" in German, "la lune" in French, and "the Moon" (upper case) in English. The word "moon" (lower case) is also used generically in English to mean a natural satellite of any planet, just as "sun" is used generically to mean any star. But the original and primary meanings of "moon" and "sun" were the specific bodies the Moon and the Sun. The Moon is sometimes referred to as Luna or Selene by English speakers, but these are poetic or dramatic uses, just as England is sometimes referred to as Albion, or the USA is sometimes personified as Uncle Sam. JackofOz 02:01, 24 March 2006 (UTC)

Similarly, the Sun is just "the Sun," despite the fact there are many suns out there. I think it should have a name of its own, and I propose Halcatalyst 03:02, 24 March 2006 (UTC)!

Isn't the Sun called Sol in some language?

I have various 4-letter names for the Sun, which I employ when I wake up and open my eyes, only to discover the Sun is burning a hole in my retina. (I have mini-blinds on the window, and the Sun has an amazing talent for finding the little holes in the blinds for the cord, and shining directly into my eye.) StuRat 03:23, 24 March 2006 (UTC)

Our sun's name is Sol, and our moon's name is Luna. They are both borrowed from Latin. —Keenan Pepper 03:40, 24 March 2006 (UTC)

I disagree. Those are the names in the Latin language, but they have never entered the English language as formal names for these places. Back when scientific papers were all written in Latin, these words would have been used. Their names in the English language are "the Moon" and "the Sun" - and our articles back me up on this. JackofOz 00:57, 25 March 2006 (UTC)

A similar point can be made about the planet we're presently living on. Unlike every other planet in our solar system, and indeed in others, our planet has no REAL name. It's simply been called "Earth" (or an equivalent in whatever other language...Terre in French, Terra in Latin,) because all those centuries ago, before we even realized it was a sphere, we basically bent down and examined what the ground was made of and named it after that. Loomis51 04:42, 24 March 2006 (UTC)

Which means that is the name of the planet. Any map of the solar system will show all the planets with their names. Ours is "Earth", or "the Earth". And of course it is a "real" name. JackofOz 00:57, 25 March 2006 (UTC)

Didn't I see the same question some weeks ago ? --DLL 17:30, 24 March 2006 (UTC)

antique phonograph motors

i am searching for information concering an antique phonograph motor manufactored by the united mfg. and dist. company. model no. 7 thank you, richard

Do you have any other info, such as the approximate date and location of manufacture ? StuRat 10:58, 24 March 2006 (UTC)

The location of the manufacture is Chicago, Ill. It gives no date on the motor. Any information could help locate which type of phonograph this is.Tks

I haven't had much luck. The most I could find out is that the United Manufacturing Company of Chicago switched to making pinball machines in the early 1950's, so your phonograph motor is likely older than that, but you probably already knew that. StuRat 22:55, 24 March 2006 (UTC)

Opioid Pain-Killers

I suffer from extreme chronic pain. Unfortunately two of my brothers are heroin addicts and the idea of taking a narcotic scares me to death. I've seen the misery it can cause. Yet I have never taken a street drug in my life and I believe that I would be incapable of resorting to the streets for drugs.

Does there exist an opioid-type drug that is extremely long-lasting, in the sense that I could take a pill, an injection or whatever once a week or so, administered by a nurse and monitored by my doctor or do all opiods have a fairly short term effect? If it could be administered to me once a week or so it would greatly relieve my fears of potential abuse, since I know myself, and I know that if administered this way there would be zero possibility of me resorting to street drugs to feed my habit, just because I know that I'm incapable of ever doing that.

I'd appreciate any info I can get.Loomis51 04:28, 24 March 2006 (UTC)

We are not doctors, and can therefore not give medical advice. Especially in a difficult situation such as this one, I would strongly urge you to consult your doctor, even if he/she can't help you directly, they will certainly know someone who can advise you. — QuantumEleven | (talk) 08:34, 24 March 2006 (UTC)

I appreciate your restraint on giving medical advice, but what I'm asking for is not medical advice per se, I'd just like to know if there exists a long lasting or extended release form of opioid-type drug. It's actually more of a chemistry/pharmaceutical question than a request for medical advice. Surely, as I said, I would only do this under the strict direction of my doctor, it's just that my next appointment is several months away and I wouldn't like to have this hanging over my head for all that time. Loomis51 11:04, 24 March 2006 (UTC)

Oxycontin is specifically designed to be a time-release drug, but it relies on its shell to be intact and slowly let out the drug into the body. Any break in the shell makes it no better than older drugs as far as a sudden dose of narcotic, and it's become a popular street drug since it can be ground up and snorted for a quick high. It takes a lot of precautions for use, but for some patients it's a lifesaver. Night Gyr 18:35, 24 March 2006 (UTC)

I don't think any of that class of meds are long lasting, and also think they are all addictive, just as you fear. To avoid the risk, I'm afraid you will need to use a different class of pain killers. Aspirin can be effective against some types of pain, especially those accompanied by inflammation, such as arthritis. Ibuprofen and other over-the-counter drugs are another alternative. Some steroids can also work as pain relievers, but have some serious side effects, too. StuRat 10:46, 24 March 2006 (UTC)

Aspirin and Ibuprofen are completely innefective in my case. Obviously, given my fear of narcotics, I would have tried them first. Loomis51 02:06, 25 March 2006 (UTC)

Also note that pain may be an indication of a physical problem which needs to be addressed. I assume you and your doctors have already looked into this. StuRat 10:46, 24 March 2006 (UTC)

Yes they have. Loomis51 02:06, 25 March 2006 (UTC)

The drug you are describing is methadone, which is sometimes used (in the US at least) for chronic pain. alteripse 11:36, 24 March 2006 (UTC)

Unfortunately, methadone is also addictive. Our article on it says: "some heroin addicts feel that it is actually harder to quit methadone than heroin itself". StuRat 20:41, 24 March 2006 (UTC)

Why would it have to be an opiate?`--BluePlatypus 13:16, 24 March 2006 (UTC)

By the way, if the pain you are experiencing is neuropathy (commonly caused by shingles or long-term diabetes), then opioids might not be the best choice. --Uthbrian (talk) 16:26, 24 March 2006 (UTC)

I'm asking about opiates because everything else has been tried on me and my doctor, who's a pain specialist told me that in a few months' time we'll be faced with the difficult decision of whether to use them on me.

Special thanks to Night Gyr. I was not aware that oxycontin was a time-release drug. How frequently must it be taken to be effective? If it's about once a week that perfect. I'd just go to the hospital and take it under the supervision of a nurse (no crushing and snorting!)

gallbladder

I have a question about the gallbladder. I am in Anatomy and Physiology so I understand the functions of the gallbladder. My question is: what happens to the bile the gallbladder normally stores after you have a cholisystectomy? Do other organs compensate for the functions of the gallbladder once it is removed or what happens to the bile it otherwise would store? Your help is appreciated. Thank you, Pat Burt

I'm not a professional surgeon, but the gall bladder just gets its bile from the liver, and dumps into the intestine when food comes along. When the gall bladder is removed the duct from the liver is connected directly to the intestine. GangofOne 07:46, 24 March 2006 (UTC)

I would think that would mean that much of the bile is wasted by dumping it into the intestines when there is no food and therefore the amount available when food does need digestion would be reduced. Thus, digestion, especially of fats, would be less effective. Most likely the person would compensate for the missing calories by eating more. StuRat 10:36, 24 March 2006 (UTC)

People who have had the gall bladder removed are advised to eat a low-fat diet. They can't digest fats as well as they could with a gall bladder, and overindulgence in fats can give them diarrhea. Brian G. Crawford, the so-called "Nancy Grace of AfD" 18:01, 24 March 2006 (UTC)

Spectra in psychology

Spectrum (disambiguation) lists two psychological spectra: the bipolar spectrum and the autistic spectrum. Are there any others? --Smack (talk) 06:48, 24 March 2006 (UTC)

After the work by Alfred Kinsey, many psychologists (including most of the reputable ones) consider sexual orientation to be part of a spectrum. Kinsey denoted it on a 0 to 6 scale - see Kinsey scale. Raul654 07:44, 24 March 2006 (UTC)

What's it like to be blind?

What is it like to be blind? By this I mean, does a blind person see blackness like a sighted person would if he closed his eyes in an unlit room? Do the optic nerves still function at all? What neural stimulation does he receive?

I went temporarily blind while undergoing LASIK (they have to use vacuum sunction to pull the eye forward in order to operate on it. Doing so causes blindness in that eye while they operate). Yes, all a blind person sees is blackness. Cup your hand over your eye, and that's what a blind person sees. Raul654 06:52, 24 March 2006 (UTC)

I don't think that's a valid analogy. For a normally sighted person to be temporarily blind, or in a dark room, or just with their eyes closed, has no necessary relationship to the experience of a person who has never been able to see. Sighted people who temporarily can't see often imagine that they can (I "see" all sorts of patterns when I cup my hands over my eyes), and in any case they know that they can see and will be able to again. I can imagine that profoundly blind people don't have this particular imagination, or that they have something completely different (and unimaginable to me) to replace it with.

We saw the same fallacy in a discussion on the Miscellaneous Reference Desk earlier this week over the question Can blind people jump?. Someone mused about blindfolding people and having them try to jump, and reasoned that if they could, presumably blind people could, too. But the blindfolded people could rely on the muscle memory of a skill learned with their eyes open, an opportunity denied to a blind person. (Now, mind you, I'm not saying that blind people can't jump, just that this wasn't a valid argument.)—Steve Summit (talk) 16:47, 24 March 2006 (UTC)

Although, for the record, I suppose there are other forms of blindness that this might not necessariy be true for. In the situation I describe, my optic nerve and the visual cortex of my brain were working fine; it was the eye that wasn't doing its job. I suppose there are other forms of blindness that this is not true for, so my description might not necessarily apply. Raul654 06:54, 24 March 2006 (UTC)

I imagine that for someone who has been blind since birth, the answer would be (Null), not (Zero (or RGB 0,0,0)). It's like me asking you what you feel from your EMF sensing organ - you don't have one so you can't accurately say "I detect no EMF field" (the correct answer would be along the lines of Mu.) Tzarius 08:09, 24 March 2006 (UTC)

It might be like that, except my (and presumably the OP's as well) EMF sensing organ is fully functional. Do remember that light is an electromagnetic field. -lethe 14:02, 24 March 2006 (UTC)

The term "blind" is used to describe people who cannot see at all. But it is also used with people who have something like a functional system for sight, but cannot see clearly enough for practical purposes. For them, the world has light, colour and contrast, but not detail. I hope that isn't oversimplifying too much. Notinasnaid 08:58, 24 March 2006 (UTC)

In the US, the term "legally blind" is used to denote those with poor vision, particularly meaning so poor that they can't get a driver's license. Note that the humorous phrase, and "Legally Blonde" movies, are take-offs on this term. StuRat 10:21, 24 March 2006 (UTC)

I do not know the name of it, but there is a form of blindness where the outer rods start to form and then stop. No cones form and the person can only sense light and dark. They cannot see any images. A friend of mine was born that way. He can tell if a light is turned on, but that is about it. It surprises people to learn that he is a programmer for Microsoft now. He's actually very good, but it always leads to jokes about blind programmers programming Windows' GUIs (which is not what he works on there). --Kainaw 14:38, 24 March 2006 (UTC)

It depends on why a person is blind. If they are blind because the back of the brain is damaged, but the eyes still work, the subconcious still gets some information cause visual data is also sent elsewhere. WAS 4.250 16:42, 24 March 2006 (UTC)

If I recall a cognitive scientist I once heard speak, the answer is something like: If the brain hardware for thinking visually is still there, then it can be done to some degree though lacking a referent it is probably not the same thing as how someone who can actually see does it. There are also issues of blindsight which is what WAS is referring to. --Fastfission 22:52, 24 March 2006 (UTC)

Gsm network

I want information about Motorola GSM 1800Mhz type designation-ctu2 Device

List of manufacturers who have supplied Refineries for Bio Disel in Brazil

Kindly inform me the contact address and phone numbers/ Mail ID of the manufacturers who have supplied and Commissioned Refineries for Bio Diesel Production in Brazil.

Representations of species of pre-humans

Hi, I realised that whenever we see artists representations of Neanderthals, Homo erectus, & all the other types of pre-homo sapien human species they are white. Is this a purely cultural construct & do African/Chinese/etc representations of these species show black & chinese versions of neanderthals? AllanHainey 12:26, 24 March 2006 (UTC)

Usually they're neither "black" nor "white", and the skin coloring and features such as eye shape vary quite a bit.. just do a Google image search for Homo Erectus and you'll see quite a bit of variation, at least in the eye of this beholder, they don't fit into any modern racial category. (Why would they?) As for Neanderthals, it wouldn't be a purely cultural construct to assume they had relatively light skin - they lived in cold climates. --BluePlatypus 13:13, 24 March 2006 (UTC)

Most primates, and indeed mammals in general, either have black skin (usually in exposed areas, like noses), or pink skin (usually under hair or fur), so it would be reasonable to assume one of those two possibilities, or some combination. Of those, I would expect black skin to be more likely, as that is the more common in current primates most closely related to us. This is speculation, of course, until we find well preserved skin frozen in a glacier or DNA from which we are able to read the skin pigmentation genes. And as BluePlatypus noted, those in the tropics would be expected to have darker skin, and those in temperate zones would have lighter skin, due to the vitamin D synthesis/genetic damage optimization based on UV exposure. If you need this explained, just ask. StuRat 13:40, 24 March 2006 (UTC)

There is also a theory accepted by very few scientists that humans are an ape-like animal that took to water (like dolphins and whales) and then came back on land. Hence, the extreme lack of hair, a nose shape that keeps water from going up it, and the little hair that does exist grows downward instead of outward (like fur) so we can move through the water easier. If that were true (a mighty big "if"), it would be highly likely that early humans had similar skin tone to the other aquatic mammals - mostly gray. --Kainaw 14:30, 24 March 2006 (UTC)

That's one wacky theory. We are quite poor swimmers compared with aquatic mammals. We don't have grey skin. We don't have blow-holes. We don't have fins. The hair we do have is frequently curly, which makes for poor fluid dynamics. We also have arched feet for climbing trees. Would those be underwater trees ? StuRat 15:28, 24 March 2006 (UTC)

I'll say it's a wacky theory. To StuRat's points I'll add: aquatic mammals all have thick blubber or very thick fur for insulation. Humans (modern ones, at least) have neither, and suffer hypothermia after an extended period in water that's at all cooler than their body temperature. —Steve Summit (talk) 16:21, 24 March 2006 (UTC)

Hmm, but wouldn't one also expect then that we'd be lighter on the belly and darker on the back too, like all aquatic mammals and most fish? --BluePlatypus 15:14, 24 March 2006 (UTC)

Or you can really go out on a limb and claim that is evidence our ancestors used the backstroke half the time.. :) --BluePlatypus 15:15, 24 March 2006 (UTC)

You might what to understand the Aquatic ape hypothesis before you misrepresent it and the evidence both for and against it. WAS 4.250 16:52, 24 March 2006 (UTC)

Yea, it's not saying that pre-humans were aquatic mammals like whales or dolphins, but only waded on shores and in riverbeds looking for food. I can buy that, but see no reason why that would effect our skin color. StuRat 17:14, 24 March 2006 (UTC)

Wow. That's actually on Misplaced Pages!? I only saw it very late one night on PBS. They had very poor computer graphics of humanoids with elongated fingers and feet flapping through the water. I found it rather humorous, which is why I remembered it. I never studied it in detail. The hypothesis in the article here is much more believable than the documentary I saw. I can believe that early humans spent a lot of time in the water, but I can't see them living in it. --Kainaw 19:08, 24 March 2006 (UTC)

Dude! This is Wikipedia. We got a millyun articles; we got articles on everything.

(Just kidding. I was impressed, too. And I take back my armchair comments above about blubber, which they explicitly address.) —Steve Summit (talk) 21:39, 24 March 2006 (UTC)

Just one query. Leaving the wacky bits aside, isn't it the case that humans are not just "ape-like animals" as Kainaw said, but are actually apes? JackofOz 00:32, 25 March 2006 (UTC)

No. The closest living relatives of man are the chimpanzees/bonobos, not the apes. You have to go back through many extinct species to find a common ancestor even with chimpanzees, however, so we aren't even particularly closely related to them. If we were more closely related, you'd expect greater similarity in speech, walking posture, and intelligence. The reason that more closely related species are all extinct is that modern humans outcompeted them. More distant relatives, however, like chimps, occupy different ecological niches (the jungle canopy, in the case of chimps), so did not compete directly with modern humans, and thus survived. StuRat 02:16, 25 March 2006 (UTC)

Sound disturbance in computer speaker when call on mobile is incoming.

I am sure many of you must have noticed this that when the computer speaker is turned on, and if a "call" or "message" is coming to a mobile kept nearby, there is a peculiar disturbance noticed in the speaker. Why does this happen? And, moreover, why does this disturbance does not occur in the mobile's "speaker" or "sound system" (If I am listening to songs on my mobile, and if call comes, then no disturbance is there on a mobile). So why does this does not take place in this case?

It's radio interference between the transmissions of the phone and the signal in the speaker cable. The broadcast from the phone's antenna as it talks to the tower is creating a current in the speaker cable which is mistaken for an audio signal and creates a sound in the speaker. The phone's own speaker doesn't have such a long cable to pick up signals and so would not be affected by the transmissions of the antenna. Night Gyr 19:01, 24 March 2006 (UTC)

It's due to time division multiple access. "A disadvantage of TDMA systems is that they create interference at a frequency which is directly connected to the timeslot length. This is the irritating buzz which can sometimes be heard if a GSM phone is left next to a radio or speakers." Apparently. Sum0 20:01, 24 March 2006 (UTC)

It also occurs before the call comes, at least in my case. Titoxd 20:04, 24 March 2006 (UTC)

It sounds like the speakers are picking up the negotiations between the tower and the handset before the call is connected. I imagine that this is similar in principle to the irritating whine of a modem connecting. For great justice. 21:59, 24 March 2006 (UTC)

It is often audible to me in the phone earpiece. It seems as if the better constructed the device is the more it will resist it. I imagine the phone itself has been designed for the most resistance to this. Its not the signal going to the speaker wire that causes it, its the RF getting into the signal wire going to the audio amplifier, that then gets pumped up and sent out via the speakers.

we're talking about computer speakers here, though, so there's no significant length of cable in front of the amp. Night Gyr 22:05, 24 March 2006 (UTC)

Airplane Engines

My mother was on an airplace recently in which the engine caught on fire when it sucked in a bird. Aren't airplace engines supposed to be able to withstand birds being sucked into thje engine?

Depends on the size of the bird and the engine. An F-22 recently suffered over six million dollars in damage when its engine was destroyed by ingesting a five-inch metal pin. See our articles on foreign object damage and bird strike. Night Gyr 22:00, 24 March 2006 (UTC)

Somewhat, but you can never design for all eventualities, for example, what about a roc? Seriously, airplane engines are designed to withstand this, but there will always be problems if foreign objects are sucked into the turbines. For great justice. 22:02, 24 March 2006 (UTC)

After edit conflict:

Also, the standard for the engine is not that it is able to survive impacts, but that the engine housing can contain all the pieces so that there are no pieces of shattered turbine impacting the fuselage or other parts of the plane. Night Gyr 22:03, 24 March 2006 (UTC)

Who knew that there were birdstrike simulators? For great justice. 22:05, 24 March 2006 (UTC)

I've been edit-conflicted out the wazoo, but I can still quote the most relevant section of bird strike for the question:

• Most large commercial jet engines include design features that ensure they can safely shut-down after "ingesting" a bird of weighing up to 1.8 kg (4 lb). Multiple or large strikes require emergency action to control damage. This limit is also applied to the rest of a modern commercial aircraft—it must be able to safely land after taking a 1.8 kg strike.

So, as Night Gyr says, the engine isn't supposed to survive, but the plane is. Melchoir 22:07, 24 March 2006 (UTC)

I've taken a class on aviation, and our instructor showed us some quite spectacular pictures of the results of a small piston-engined plane's encounter with a flock of birds. The propeller cap and much of the leading sheetmetal was dented, and there were feathers and blood everywhere. They were small birds, though, so the plane survived. Night Gyr 22:15, 24 March 2006 (UTC)

Impressive. Well, now I have to post this link for the single jet-engine case, and I'll be done: birdsuck.wmv CT155202.pdf Melchoir 22:27, 24 March 2006 (UTC)

I feel the need to mention this case... Shimgray | talk | 01:05, 25 March 2006 (UTC)

March 25

Cleanrooms for personal use

Though cleanrooms are used in semiconductor manufactoring,biotech and the life sciences due to my desire to live in a "clean" enviornment I seek to have one installed in my house. Though I run under a limited budget I would like to know if it is possible to have it installed in a normal house and if so how much would it cost for me if I wanted a sterilized class 10 cleanroom. Though this is indeed a very odd question it is of utmost importance to my well being and as such I ask you to reply seriously. Thank you very much for your time.--Ishikawa Minoru

Sorry if this seems dismissive, but you should consider seeing a psychiatrist instead. It would be much cheaper, and better for you in the long run. —Keenan Pepper 01:14, 25 March 2006 (UTC)

He might have an actual need, such as severe, life-threatening allergies to just about everything. StuRat 02:04, 25 March 2006 (UTC)

Bubble boy? - Cybergoth 02:15, 25 March 2006 (UTC)

The Elder Scrolls' fnt+tex files... LaTeX?

I'm attempting to edit or create fonts compatible with The Elder Scrolls III: Morrowind and The Elder Scrolls IV: Oblivion. The existing fonts appear to be sourced from two matching files, one a .fnt and the other a .tex. You can see an example pair here (.fnt) and here (.tex). However so far I haven't come up with much. Are these LaTeX (or a variation) or are they merely an in-house format?

Thanks in advance. :) Garrett 00:39, 25 March 2006 (UTC)