Wikipedia:Reference desk/Archives/Science/2006 October 5

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Breaking your own neck

I was cracking my neck today when one of my classmates stopped me and told me a rather interesting story as to why I shouldn't crack my neck. He said that his brother died -- of cracking is own neck. Apparently, his brother was playing a pickup game of basketball and dunked, and had a kink in his neck. He tried to crack it by twisting and "died instantly" by breaking it. Is this possible? I am very skeptical of this, and I was wondering what you guys think about it. Thanks for any responses. --ClockFace 01:54, 5 October 2006 (UTC)[reply]

Nah, that wouldn't happen. First, cervical fractures don't result in sudden death. So your friend's brother, even if he was able to break his own neck, would not have died instantly. According to Moore and Dalley's Clin. Oriented Anat. (5th ed., Lippincott Williams and Wilkins, 2006), 40% cervical fractures are due to hyperextension (as in a hangman's noose), and 45% are due to horizontal blows. The book also mentions that almost all fractures are accompanied by tears in the ligaments surrounding the bony processes of the vertebrae. Since these ligaments are heavily innervated, it would be extremely painful to rip them, and since that pain would precede any fracture (or subluxation) that could lead to spinal cord fracture, it is very unlikely that one would even be physically able to perform such an act purposely, and nearly impossible to do it accidentally. For a short article on back cracking, see [1].Tuckerekcut 02:47, 5 October 2006 (UTC)[reply]

Thanks for the quick response, Tucker. I didn't think it was true. Again, thanks for the help. --ClockFace 03:01, 5 October 2006 (UTC)[reply]

It is a little curious that your classmate claimed it was his own brother who died instantly. Most urban legends and exaggerated nonsense are told of a FOFA (friend of a friend) which of course are never verifiable and are nearly always grounds for immediate skepticism. It should be relatively straightforward for you to find out your classmate's name and find out if his brother died. Then it becomes a matter of whether his understanding or account of the death is accurate. alteripse 04:16, 5 October 2006 (UTC)[reply]

This is a cliche of some action movies: a skilled assassin is captured. He glares at the good guys, then grabs his own head and snaps his neck, and dies instantly. It is more common to see a martial arts expert in such a movie grab someone else's head, give it a quick twist, and cause the instant death of the victim. It never looks like sufficient force is applied over sufficient rotation to cause such an effect. The tally of cervical fractures due to hyperextension and horizontal blows does not seem to include the classic accident of diving into shallow water and breaking the neck when the head hits bottom. That would seem to be vertical compression, or does it act through the head rotating?Edison 14:18, 6 October 2006 (UTC)[reply]

Wouldn't it be hyperextension? The head hits, and moves off to the side to make room for the body still coming—like being hanged, but upsidedown. — X [Mac Davis] (SUPERDESK|Help me improve)01:17, 7 October 2006 (UTC)[reply]

Scar Healing?

As the result of what I believe to be flea bites a few weeks ago, I have several raised scars on my left arm, and one sunken scar. How long will it take these to heal? Our article doesn't say. Thank you! -Fsotrain₀₉ 01:59, 5 October 2006 (UTC)[reply]

If they really are scars, then they may never fully return to the original condition. StuRat 05:07, 5 October 2006 (UTC)[reply]

He might mean scab, which would at least explain the elevated scars. freshofftheufo ΓΛĿЌ 11:39, 5 October 2006 (UTC)[reply]

Ask a doctor when you want medical advice, but I have seen scars diminish over at least a six month period.Edison 14:19, 6 October 2006 (UTC)[reply]

Color of blood

Why is it that when you bleed, the blood is bright red, yet when you have a blood sample taken, or give blood, its more of a darkish maroon color?--Light current 04:07, 5 October 2006 (UTC)[reply]

When blood hits the air the hemoglobin immediately oxygenates, which changes its color to bright red. In the veins and in vacuum tubes the unoxygenated blood is much darker maroon, even bluish. alteripse 04:11, 5 October 2006 (UTC)[reply]

See also the "Colour" section of Blood. DMacks 04:17, 5 October 2006 (UTC)[reply]

which of course, is a good example of coordination chemistry. Xcomradex 05:34, 5 October 2006 (UTC)[reply]

THank you. THat explains it perfectly to me.--Light current 13:02, 5 October 2006 (UTC)[reply]

Gyro effect on bicycles

I we didnt have the gyroscopic effect of the wheels on a bicycle, how difficult would it be to maintain balance?--Light current 04:35, 5 October 2006 (UTC)[reply]

Try balancing a stationary bicycle and you will know exactly how hard it is. StuRat 04:43, 5 October 2006 (UTC)[reply]

On which hand? 8-)--Light current 04:46, 5 October 2006 (UTC)[reply]

Note that the gyroscopic effect is not the main reason a bicycle stays upright, that's a common misconception. Take a look at bicycle and motorcycle dynamics, which covers this pretty well. — QuantumEleven 09:33, 5 October 2006 (UTC)[reply]

Is a gyroscopic effect at all related? —Bromskloss 10:09, 5 October 2006 (UTC)[reply]

Yes, slightly. Gyroscopic precession helps to steer the front wheel in the direction in which the bike is leaning (see section 1.3 of the article I linked above). This helps to make steering faster and riding "with no hands" easier, however, it barely has any impact on keeping a moving bike upright. — QuantumEleven 11:25, 5 October 2006 (UTC)[reply]

Ah, I see it now. The image I send along actually says it all. In any case, it must be scary to ride a bike with a negative Caster angle, since I guess it would would steer in the wrong direction when you're leaning. One would have to fight against it with ones arms all the time. Heh. —Bromskloss 14:01, 5 October 2006 (UTC)[reply]

THanks for the ref to bicycle and motorcycle dynamics. It seems to have the discussion I was looking for.--Light current 13:11, 5 October 2006 (UTC)[reply]

sulbutiamine

how the drug sulbutiamine act on memory

Search first, it's quicker! See our article on sulbutiamine for everything Wikipedia knows about this drug, including its effects and mode of action. --Robert Merkel

PAL

Does anyone know what is the difference between PAL I and PAL B/G. In particular, can a camcorder purchased in a country where PAL I is used be utilized as is in a country where the PAL B/G is in use?

Broadcast television system will answer the first part of your question. I don't know whether it will answer the second. --ColinFine 23:57, 6 October 2006 (UTC)[reply]

74161 IC

can i get the internal functionality of a 74161 IC (a 4 bit binary counter with ripple carry output) —Maleka 05:51, 5 October 2006 (UTC)[reply]

I dont think we have the data sheet here. Try googling 74161--Light current 13:14, 5 October 2006 (UTC)[reply]

Mabye this is it: Synchronous presettable binary counter with clear Found via DatasheetArcive. —Bromskloss 13:42, 5 October 2006 (UTC)[reply]

TV scanning method

The current TV scanning method makes a scan of around one line in one direction(horizontal) before it gets off and starts over again in the beginning of the next line.Instead,why cant it scan from the end of the next line to the beginning after the initial scan, so that it can save time and have better quality picture?

Interesting point. Mabye it was considered to be easier to construct the electronics for the sweep as it is instead of the way you suggest. In any way, I don't think there ever was a need for a faster sweep. Probably you don't want a too fast sweep because that would give your signal (that is to be transmitted to the TV audience) a greater bandwidth, which makes it take up more space in the frequency spectrum.

One could imagine doing the same thing for the vertical sweep, but then there would be another problem because that sweep is much slower than the horizontal sweep. If you start at the top, sweep down, then start a new sweep from the bottom and go up again, you would return at the top after twice the time it takes with a normal sweep. That could possibly create flicker since the screen would have more time to fade out before being lit up again. (There would be increased flicker only at the top and bottom, not in the middle, since the sweep would get there equally often as with normal sweep.) —Bromskloss 10:23, 5 October 2006 (UTC)[reply]

Given the way cathode ray tubes work, it'd just make things more complicated. You'd have to have a triangle wave-like voltage variation in the horizontal deflection coils, instead of the sawtooth wave you get from the current sweep mode. The sawtooth wave is much simpler to generate with basic electronic components, one of which is the flyback transformer used in CRTs. The flyback is a especially built high-frequency transformar that operates this way, with the electromagnetic field collapsing very quickly once the input voltage pulse ceases. This quick drop in the field is what causes the beam to go all the way back to the left of the screen almost instantly (hence the name "fly back"). ☢ Ҡi∊ff⌇↯ 10:41, 5 October 2006 (UTC)[reply]

No. you dont need a triangle vave voltage variation at the defl coils. You need a square wave. THe coils act as integrators. see inductor 8-|--Light current 14:57, 5 October 2006 (UTC)[reply]

Ah, nice information. So, how do ordinary oscilloscopes do it? I mean, they are capable of producing an arbitrary waveform. —Bromskloss 11:34, 5 October 2006 (UTC)[reply]

Oscilloscopes don't work by scan, they're vector displays. They have two different signals for horizontal and vertical scan, and that's what creates the image (which is nothing but a trail left by the beam) ☢ Ҡi∊ff⌇↯ 11:45, 5 October 2006 (UTC)[reply]

Yes, yes, I know! My point was that since the deflection isn't a sawtooth, one can't use a flyback transformer. Btw, I actually once did feed an oscilloscope with sweep signals (and switched the beam on and off) to produce TV-like images. I connected it to a Space Invaders game. —Bromskloss 13:13, 5 October 2006 (UTC)[reply]

Oscilloscopes use an entirely-separate high-voltage power supply. Simple 'scopes used to just have a high voltage winding on the power transformer with a half-wave rectifier (e.g., a 1A2) or sometimes a voltage multiplier. More sophisticated oscilloscopes use a high-frequency oscillator and a relatively-small step-up transformer. And modern 'scopes, of course, are just PCs with LCD displays and fancy analog input peripherals, so they dodge the entire question!

Atlant 16:15, 9 October 2006 (UTC)[reply]

Just first thoughts on this.(analogue TV)

I cant see a real problem with generating a tri wave scanning current: Just apply a sq wave to the scanning coils which act as an integrator.
The TV camera would need to scan in the same way to get the correct lum and color at the correct place in the screen
There may be some problem with synchronisation of a triangle wave as it doesnt have a nice clean edge. I suppose it could be differentiated to give a square wave. ATM, there is a horiz sync pulse transmitted at the start of every line: there would be no time to do this with a tri wave. With color transmissions, a color burst signal is sent immediately after the sync pulse to sync the color circuits.

More thoughts as they come to me --Light current 14:51, 5 October 2006 (UTC)[reply]

More thoughts:(analog TV)

The line output transformer is also used to generate the eht voltage for the tube CRT. THis may need modification to work with triangular timebases.
All sync info would need to be transmitted at the positve and negative peaks of the tri wave. THis may not be too much of a problem.
Im not sure how much increase in picture quality would be evident. In 625 line TV, a line takes 64us of which 12us is used to allow flyback. This would mean a 23% increase in horiz pixels (neglecting any need for sync and color burst.

Basically, time is needed at the end of every line to transmit the synchronisation info. Otherwise, it would have to be done with a speartate sub carrier that would increase the transmission bandwidth.--Light current 16:18, 5 October 2006 (UTC)[reply]

Well I really dont think the bandwidth would increase because there are two fields of scanning, the even and odd.So guess bandwidth remains the same.Any reason why this has not become standard?

Also, (from broadcast television system) "Since the electron beam must be turned off in any case, the result is gaps in the television signal, which can be used to transmit other information, such as test signals or color identification signals."--Shantavira 09:01, 6 October 2006 (UTC)[reply]

M

Hello all. I have a power point on the chemistry behind acid rain due tomorrow, so i looked at the acid rain article. My question:

SO2 + OH· + M→ HOSO2· + M

I don't know what the M stands for. Someone please tell me.203.122.81.148 09:56, 5 October 2006 (UTC)[reply]

M commonly stands for metal, but I couldn't find one which would logically be involved in the reaction. It depends entirely of the metal content of the affected area, water, soil, or building. - Mgm|^(talk) 10:33, 5 October 2006 (UTC)[reply]

obviously u are someone in South Island School hong kong (the one who posed the question) and in year 10.—Preceding unsigned comment added by 219.78.207.123 (talk • contribs)

How is that relevant? It's a reasonable question and certainly the acid rain article should be clarified on this point.--Shantavira 12:04, 5 October 2006 (UTC)[reply]

The explanation is in the talk page of acid rain. It's really esoteric (purist), and I haven't found it anywhere else, nor is there an inline reference to it. Here's the quote from the talk page: "It represent any third body. In Earth's atmosphere this is almost always N2 or O2. If you consider the reaction with just two bodies reacting together to give a single product e.g. OH + NO2 = HNO3 then it is impossible to conserve both momentum and energy simultaneously just by looking at the velocity of the product. The extra energy becomes internal energy in the product and this will tear the new molecule apart unless it colides quickly with some other molecule 'M' to remove this energy. This M is the conventional representation of this process in chemical kinetics." --Zeizmic 13:52, 5 October 2006 (UTC)[reply]

There is nothing happening to the M, i.e. it goes in as M and comes out as M. So it may be a catylist (In which case it shouldn't be placed in the equⁿ. Englishnerd 22:04, 5 October 2006 (UTC)[reply]

mass

what is the definition of mass in terms of quantum mechanics? i cna't find it in the quantum mechanics article nor the mass article. Thanks!

Oh, I'm sorry. The question probably has to do with mass-energy equivalence. Check out the, E=mc² article. — X [Mac Davis] (SUPERDESK|Help me improve)13:10, 5 October 2006 (UTC)[reply]

It's part of the standard model, but maybe the Higgs boson will help you -- it's the (still theoretical and un-observed) particle that allegedly plays a role in the origin of mass. -- Plutortalk contribs 14:09, 5 October 2006 (UTC)[reply]

You don't mean allegedly, you mean hypothetically. The former has connotations of a dispute, which is certainly not the case—we just don't know yet. -- SCZenz 01:49, 6 October 2006 (UTC)[reply]

Drippy Iron

Why does water drip from the holes in my clothes iron, instead of shooting out as steam, like God intended? --Username132 (talk) 13:58, 5 October 2006 (UTC)[reply]

Haha! :-) Could it be clogged? —Bromskloss 14:25, 5 October 2006 (UTC)[reply]

Er, that'll be because the water hasn't reached boiling point? Most irons will have a steam setting. Wait until it starts hissing. Or maybe it has a leak or a worn washer on the steam valve.--Shantavira 14:31, 5 October 2006 (UTC)[reply]

Clogged is a good bet. You have to put through the nasty de-scaler stuff, which is really fun to inhale as a mist. --Zeizmic 17:37, 5 October 2006 (UTC)[reply]

Your iron probably has a metal sole plate on the bottom with holes, and a space behind that soleplate. When you push the steam button, water is squirted onto the inside surface of the plate. If the plate isn't hot enough to boil the water immediately or if there is too much water, then it will drip out as a liquid instead of escaping as steam.Tuckerekcut 22:19, 5 October 2006 (UTC)[reply]

Chlorofluorosulfonic acid

I just read a dutch text about chlorofluorosulfonic acid (chloor-fluor-sulfonzuur, incase my translation is incorrect) being injected in the outlet gases of the B-2 Spirit bomber to improve its stealth properties and wanted to find out more about it. Internet searches however came up with nothing, so I'd thought I'd ask my questions here.

Does chlorofluorosulfonic acid exist or did the text just mean a mix of fluorosulfonic and chlorosulfonic acid?
How would adding chlorofluorosulfonic acid to the exhaust stream contribute to reducing the detectability of it?

- Dammit 14:39, 5 October 2006 (UTC)[reply]

How are the oil well fires extinguished?

I don't know in the general case, but in the first Gulf War I believe they bombed the wells to deprive the fire from oxygen. - Dammit 15:00, 5 October 2006 (UTC)[reply]

No, wait. Wikipedia actually has an article on it. You're confusing the science reference desk with Google. - Samsara (talk • contribs) 15:36, 5 October 2006 (UTC)[reply]

This gives a pretty good explanation. Clarityfiend 15:39, 5 October 2006 (UTC)[reply]

Explosives are generally detonated near the wellhead, driving the fireball away from the fuel source, momentarily interrupting the source of heat which sustains the fire. Red Adair was definitely the go-to guy on this topic.

Atlant 16:18, 9 October 2006 (UTC)[reply]

human proteins in plant cells

can human protiens be synthesised in plant cells??

Yes, certainly. Both plants and animals are eukaryotes, and as such use essentially the same DNA transcription format as one another. – Clockwork Soul 20:39, 5 October 2006 (UTC)[reply]

It probably depends on the protein and the plant cell - some proteins need to be folded and cut in a certain way and the plant cell in question may or may not have the necessary enzymes to do this for the protein in question. Of course you could also provide the DNA sequence for all the necessary enzymes (and the enzymes involved in their manufacture (and so on)) but it might start to get prohibitively difficult/expensive. --Username132 (talk) 15:05, 9 October 2006 (UTC)[reply]

identify a gene

how can i identify a gene responsible for a particular disease?

How do you know the particular disease is genetic, and that it is only a gene? DMacks 15:50, 5 October 2006 (UTC)[reply]

Go to the Online Inheritance in Man website, here. Enter the name of the disease in the search box, and hit "Go". This should give you some idea of the current state of knowledge about the genetics of the disease. - Nunh-huh 18:55, 5 October 2006 (UTC)[reply]

Just a few remarks, rather unconnected, as I'm not an expert: (1) A disease is obviously genetic, if it's inheritable. So, if scientists notice that a disease always runs in families, they might start looking for a gene. (2) A good strategy might be to compare children of somebody with the disease. If one sibling is ill and the other is not, one should look at the differences between their genomes. Of course, there would be way to many. (3) For many diseases the probability of its outbreak is enhanced by the presence of a genetic predisposition. Schizophrenia is a good example. But even if the predisposition is present, outbreak is not sure. There seem to be more causes. (4) There exists quite some confusion of what is meant by "one gene". Mendel did not know about DNA, and so, he called one gene the cause for one phenotypic effect that he could distinguish. But, of course, a phenotypic effect is ultimately the cause of the interplay of all genes, because even if the information about the colour of the iris were in fact stored only at one locus, still the whole information about how to make an iris is involved. Also, traits such as body height are the sum of many effects. Modern genetics hence likes to call one gene the information that describes the composition of one protein. (5) This is why most genetic diseases that the press writes about are metabolic diseases: some enzyme is missing that is crucial for some body function. Hence, once one has understood the [etiology]] of a disease so far that one can pinpoint which protein is not correctly synthesized, one may try to find this protein's primary structure which one then translates into the genetic code and looks in the human genome databases for this sequence. Then, this is probably the locus where to look for alterations in sufferers of the illness. But, it is only so easy, if the disease is about the lack of one specific enzyme. And any real experts around (I'm a physiscist, not a molecular biologist), please correct me in case I'm wrong. Simon A. 20:22, 5 October 2006 (UTC)[reply]

Actually, a heritable disease don't have to affect one's DNA. The idea that heritable diseases are always the result of a mutation in germline DNA, while frequently correct, is definitely not the only possibility. It's been demonstrated that phenotypes can be transmitted from parent to offspring by RNA alone (lookup PubMed ID 17126949), which the human body (or any mammal as far as I know) cannot translate back to DNA. Furthermore, it's possible for changes in chromatin state to be transmitted, but I don't recall a source for that. StevenBrown 18:27, 30 December 2006 (UTC)[reply]

One correction, "running in families" is necessary, but not sufficient, to establish that a dice is genetic. Diabetes, for example, may run in families in part because other contributing factors, like a sedentary lifestyle and poor diet, are passed down from parents to children. In the case of diabetes, there is also be a genetic factor, which can be demonstrated when children are raised in a different environment and still manifest an increased incidence of diabetes relative to the general population. StuRat 10:55, 6 October 2006 (UTC)[reply]

The preference for a sedentary lifestyle might have a genetic component, as might dietary preferences. Cultural versus genetic influences can't always be distinguished by inspection.Edison

Yes, but those things aren't solely genetic. Foods tend to vary by culture. US fast food preferences are spreading to other countries, for example, and this is not a genetic thing. StuRat 19:13, 7 October 2006 (UTC)[reply]

On ocean ecology

Why is ocean fauna more diverse in temperate, and not in tropical areas?

I don't think it is. The diversity of an aquatic habitat relies on two major factors: accessability to nutrient and sunlight. Some areas, like the centre of the ocean, have very low diversity. Even though the ocean has immense areas exposed to sunlight, there's very little essential nutrients required for organisms to survive, and they cannot survive in large numbers. Even marine environments close to the continents have low nutrients in comparison to fresh water systems on the continent. This is because forests and estuary systems will use them up before they reach the ocean. Because of all this, it is very dependent on the actual location (not latitude) as to the diversity of the area. Coral reefs have huge diversity (probably the highest marine diversity), and they are in tropical regions. It is due to the biology of the coral, as the nutrient is still low. --liquidGhoul 15:25, 5 October 2006 (UTC)[reply]

is vaccinatiom possible?

why do people respond differently to a particular allergen?is vaccination possible against an allergy?

Hyposensitization is the closest. If you think about it for ten seconds, you may realise that "vaccination" can only really induce allergies, as the principle underlying vaccination is to induce an immune response. - Samsara (talk • contribs) 15:33, 5 October 2006 (UTC)[reply]

Please don't bite. If the questioner had enough information to get the answer after ten seconds of thought, they probably wouldn't have asked the question.

I don't know of any way to prevent specific allergies, as one prevents specific diseases with a vaccination. One may be able to slightly reduce the risk of allergies in general by exposure at a young age to many different allergens, thus training the immune system not to overreact; on the other hand, some health care workers seem to think this makes allergies more likely because exposure always precedes allergy development. For more information, see Allergy#Basis_of_increasing_prevalence. Hyposensitization is a treatment, not a prevention, used after the allergy has been acquired. --Ginkgo100 ^{talk · e@} 20:17, 5 October 2006 (UTC)[reply]

Vaccination against allergies is a possibility currently being worked on: Vaccination against food allergies and Hay fever vaccine. Rmhermen 21:54, 5 October 2006 (UTC)[reply]

It is unknown why some people respond to allergens differently. There are several theories. Genetics plays a role. Exposure to certain allergens at certain times during early childhood might also. Exposure to "dirt" early in life seems to alleviate allergies. As for vaccination, there was actually an interesting article in this week's New England Journal of Medicine which details a trial of a new immunotherapy against allergic rhinitis due to ragweed. It seems that vaccination (in a sense) is possible to treat allergies, though nothing to my knowledge has been shown to prevent them. InvictaHOG 00:12, 6 October 2006 (UTC)[reply]

Overdose

(moved from talk page)

250 mg caffeine is an acute overdose, is it 250mg per KG weight?

Here in sweden you can buy caffeine-tablets (100mg caffeine each), how many could I take befor reaching 250mg if my weight is 60kg?

- Unregistered usr —Preceding unsigned comment added by 213.64.150.116 (talk • contribs)

250mg per kg weight probably will kill you. I remain in hope that this was not your idea of a fun evening. - Samsara (talk • contribs) 15:30, 5 October 2006 (UTC)[reply]

Hey, I'm not dumb, just wanna know how much I possibly can take before getting close to that number. —Preceding unsigned comment added by 213.64.150.116 (talk • contribs)

If you're not dumb, I'm sure you can read the article and understand. If you can't do the maths, use the calculator tool your operating system doubtless provides. - Samsara (talk • contribs) 15:40, 5 October 2006 (UTC)[reply]

Why? tablets usually have dosing directions on the box. You could just follow that. pschemp | talk 15:41, 5 October 2006 (UTC)[reply]

250x60=15000. 15000/100=150. So I could take 150 tablets before getting an overdose? Even half of that amount (75) sounds very much. Feels like you can't overdose caffeine... thx anyway then..

Per the "Overuse" section of caffeine: "In cases of extreme overdose, death can result. The median lethal dose (LD₅₀) of caffeine is 192 milligrams per kilogram in rats. The LD₅₀ of caffeine is dependent on weight and individual sensitivity and estimated to be about 150 to 200 milligrams per kilogram of body mass, roughly 140 to 180 cups of coffee for an average adult taken within a limited timeframe that is dependent on half-life. Though achieving lethal dose with coffee would be exceptionally difficult with regular coffee, there have been reported deaths from intentional overdosing on caffeine pills." – Clockwork Soul 18:01, 5 October 2006 (UTC)[reply]

I used to take 400mg pills (coated in chocolate) every day to jack me up when I started a new job after being out of work for a while (and used to sleeping in), no problem. I do not think you will have a problem with a 100mg pill unless you are a real small person and not very healthy.

Father of the Solar Cell

Who is the father of the solar cell? The Wikipedia information on this question is confusing. Hassan Kamel al-Sabbah is supposedly the "father of the solar cell", according to the Wikipedia article on him: http://wiki.riteme.site/wiki/Hassan_Kamel_Al-Sabbah

But all other references to the solar cell (http://wiki.riteme.site/wiki/Solar_cell) do not reference him in the history. Instead, the articles reference Charles Fritts and Russell Ohl.

I'm wondering why Kamel al-Sabbah is omitted from other solar cell references. I'm also wondering why the first Wikipedia article refers to him as the father of the solar cell? ---***

The Hassan Kamel Al-Sabbah article is typical of the species of wikipedia articles which are overwrought at best, most likely vanity, and quite possibly total nonsense. It cites no sources, it contains silly vain language like "par excellence", and its contributor did little but add this article. Googling for him finds very little that isn't a wikipedia mirror. He's a minor player at best, and you shouldn't trust that article at all - it should quite probably be deleted. Middenface 16:17, 5 October 2006 (UTC)[reply]

Deleting the article would be extreme. It can be easily fixed. I took out the "par excellence" and "father of the solar cell" myself. Others can fix anything else that's wrong with the article. StuRat 09:41, 6 October 2006 (UTC)[reply]

One of the weaknesses of Wikipedia is that people who admire an inventor can put any sort of overwrought language in an article and by their numbers and persistence wear down anyone who seeks to tone down the hyperbole. Witness the Nikola Tesla article: "Tesla is regarded as one of the most important inventors in history." and "In the United States, Tesla's fame rivaled that of any other inventor or scientist in history or popular culture." By reverting, these unsourced statements are kept in the article.Edison 14:45, 6 October 2006 (UTC)[reply]

So you think it would be better to have no article on Tesla at all ? StuRat 19:05, 7 October 2006 (UTC)[reply]

In this case I would say that if enough people think he's famous then obviously he is. :) But joking aside, you're right this is exemplary of the major weakness of Wikipedia. That said, any source making similar claims displays POV. A strength of Wikipieda is that such POV's can be reverted by others. Even though Wikipedia is not supposed to be a democracy, effectively it is. A major strength of other encyclopedias is that the POV's generally come from informed people. Now if only we could have sort of a democracy of experts on Wikipedia. We would need a good way to establish peopl's expertise on various subjects, so we can restrict (certain types of) edits to them. That would also imspire them more, knowing that if their edits are reverted, at least it will be done by someone who knows what they are doing. DirkvdM 08:06, 8 October 2006 (UTC)[reply]

We seem to have that now, in the science and math fields. While it leads to technically correct articles, they are also completely unreadable by anyone lacking a PhD in that particular field. This is not a good thing. StuRat 03:36, 9 October 2006 (UTC)[reply]

Mystery bird

My sister (who lives near Charleston, South Carolina, U.S.) has a cat which recently caught a bird. She says it looks exactly like a Pheasant Coucal (off-site info and photo here), but that species is native to Australia. Wikipedia doesn't tell me anything about the range of its relatives. Does anyone know what species this bird could be? Are Pheasant Coucals introduced in North America? --Ginkgo100 ^{talk · e@} 20:32, 5 October 2006 (UTC)[reply]

It could be a pet bird that escaped. StuRat 09:26, 6 October 2006 (UTC)[reply]

science

What animal was rediscovered in 1938 was believed to have gone extinct with the dinosaurs and has proto legs

Coelacanth. alteripse 21:16, 5 October 2006 (UTC)[reply]

Thats your homework done for this week!--Light current 01:38, 6 October 2006 (UTC)[reply]

Other pde5 inhibitors, besides sildenafil, tadalafil and vardenafil

I know that there are at least two new phosphodiesterase inhibitors to treat erectile dysfunction (I read about them doing a search, but can't finde them any more). Anybody can help me with their names?

CGMP specific phosphodiesterase type 5 says "There are now three oral ED drugs; Viagra, (sildenafil) by Pfizer; Levitra (vardenafil) by Bayer Pharmaceutical and Glaxo-Smith-Kline-Beecham/ Schering Plough; and Cialis (tadalafil) by LillyICOS." I've only heard of the three, and they're not in WP yet, so they must be quite new (I would think that penis pills would get some attention). – ClockworkSoul 22:03, 5 October 2006 (UTC)[reply]
- There are several erectile dysfunction pills, however, that are not PDE5 inhibitors: Alprostadil, Apomorphine, Moxisylyte, Papaverine, Phentolamine, Yohimbin are examples. – Clockwork Soul 22:07, 5 October 2006 (UTC)[reply]

There were only 3 FDA approved products in 7/06 and none seem to have been approved since according to the FDA page. InvictaHOG 00:06, 6 October 2006 (UTC)[reply]

Rm3

m^3 as we all know is cubic metres.

What is Rm^3?

Could you give some more context? For instance where did you read/find it? - Dammit 22:07, 5 October 2006 (UTC)[reply]

I don't think it is realated to Metres, R isn't an SI prefix. What is teh context? Englishnerd 22:18, 5 October 2006 (UTC)[reply]

Could it be to do with this or this?--Shantavira 09:18, 6 October 2006 (UTC)[reply]

I was looking for this too after seeing it in a paper on hydrocarbon migration. I believe it stands for "reference cubic metres" but why it is necessary or who started it or when I do not know yet. steve 04:32, 5 December 2006 (UTC)[reply]

Cure for oedipus complex?

People keep saying that I have an oedipus complex because I find myself mostly attracted to 40+-year-old women (MILFs in other words). Is there any way of 'curing' myself of this 'problem' (I don't know if I see it as one)? Would picking up MILFs in bars for sex regularly help me 'get it out of my system'? --84.67.222.102 22:21, 5 October 2006 (UTC)[reply]

Urr, the oedipus complex is a subconscius desire for your own mother, which is not quite what your getting at I think... At least I hope not. Philc _T^E_C^I 22:26, 5 October 2006 (UTC)[reply]

What's it called then, when a young-ish guy is exclusively attracted to middle-aged women? --84.67.222.102 23:52, 5 October 2006 (UTC)[reply]

Ashton Kuchie Kuchie Kucheritis? Clarityfiend 00:12, 6 October 2006 (UTC)[reply]

If this is the same teenager from before, about 20 years oughta do it. Clarityfiend 23:47, 5 October 2006 (UTC)[reply]

I'm not a teen, I'm in my early 20s. Women my own age don't interest me at all, no matter how attractive they try to make themselves look. Give me a woman in good shape who's about 43, but dresses like a 20-year old with bleach blonde hair, big breasts and an hourglass figure and I go crazy. I don't understand it either, I think I've always been like that. --84.67.222.102 23:58, 5 October 2006 (UTC)[reply]

If you don't think your sexual preferences are a problem then don't let others convince you that it is. That being said, sexual preferences can easily change over time, so this might be a passing interest. Or, it might not. But it isn't a disease, so you can't "cure" it. --Fastfission 23:49, 5 October 2006 (UTC)[reply]

When you're 100 years old, will you be exclusively attracted to 120 year old dead women ? StuRat 00:28, 6 October 2006 (UTC)[reply]

Let's first say that Freud's really old idea of the Oedipus complex is not taken too serious any more by today's psychologists. But, as Philc pointed out, it's not the right term any way. Being no psychologist, I only have common knowledge advice for you. There's two obvious solutions: (1) Wait 15 years, and you'll be attractive for typical 40+ women. Ok, maybe that's not a solution. (2) Find a 40-year old woman who feels attracted to young men. I'd say this should exist though not easy to find. Good luck with hunting. In any way. don't consider it an illness. Talk to your male friends and you'll notice how vastly male taste in women differs. Only fashion magazins claim that all men like anorexic teens. But maybe it helps to try to figure out what it is that attracts you. The physical or the mental maturity? If the latter don't forget that this can be found with all ages. Any way, good luck. Simon A. 07:21, 6 October 2006 (UTC)[reply]

From evolutionary psychology, a young male who is not yet capable of supporting a family of his own will try it on with older women and try to get a sneak mating to cuckold their real older partner, so you get the offspring but without the investment. On this basis, when you're a bit older and capable of supporting a family you should grow out of it and start looking for a mate who is a bit younger than yourself.

The Joy of being a Boy Toy! And don't forget the basic math: 20 goes into 43 more times than 43 goes into 20.Edison 14:49, 6 October 2006 (UTC)[reply]

43 is a prime number.

Chemical prices

For prices listed by the pound and the gallon in Chemical Commodities Monthly (ICIS Pricing), what molar percent purity are the prices for? Submitted by Hydnjo, 20:02, 5 October 2006.

i imagine it varies manufacturer to manufacturer. try contacting the manufacturer of the compound of interest. Xcomradex 00:25, 6 October 2006 (UTC)[reply]

false. It does not vary, it's a commodity there is an industry standard. You can't just call up Exxon-Mobil and ask them what percent purity their benzene is distributed in. Submitted by 70.225.175.198, 22:00, 5 October 2006.

you can certianly call up up exxon and ask for the specifications of their products, just go to their website. and you can certianly call this petrochemical company[2] up and get their %purities. doesn't sound standardised to me. Xcomradex 02:52, 6 October 2006 (UTC)[reply]