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particles are always in what
Please clarify your question. What, exactly, do you want to know? --Ashenai (talk) 22:30, 4 October 2005 (UTC)
- Maybe it's a riddle...? -- SCZenz 00:47, 5 October 2005 (UTC)
- constant motion?--Michael 04:28, 9 October 2005 (UTC)
Heroin in Food
I know this sounds crazy,but I NEED to know EVERYTHING that happens to the human body,if you EAT heroin.I have even gone on sites in New Zeland and Austrlia trying to find the answer to this ?.I have found nothing anywhere!I want to know how it breaks down chemically,amounts in blood verses stomach contents,morphine to 6MAM,how long it takes to die.I think you get it.Thank-You for ANY answers you can give me. Toni I'm sorry!I did not mean to send this twice.Until my daughter died I,I wasn't even sure how to turn one on.
Search medline for heroin overdose like this [1]. You get hundreds of hits. You will have to sift for those that might describe oral overdose, like this PMID 10829332. Look at its bibliography for previously published articles on oral overdose. What you really want is something that describes the characteristic effects of oral OD vs injected OD because the latter is hundreds of times more common. Alternatively, go to a medical school library and ask for some toxicology and drug abuse texts. Look at the references to their chapters. I assume you are not dealing with an oral OD at this minute? If so, get him to the ER. alteripse 23:41, 4 October 2005 (UTC)
- One warning - medical journals are written for doctors and scientists to communicate with each other, and consequently they assume a *lot* of background knowledge that doctors or biological scientists receive as part of their college training. It may take you some time and a fair bit of reading to familiarise yourself with the relevant background (though the Wikipedia is a reasonably good place to get a lot of that background), but it's by no means impossible. Many articles will also use some statistics, so you may need to learn a bit about that. Good luck, and I hope you find what you are looking for, whatever that is. --Robert Merkel 01:01, 5 October 2005 (UTC)
- If you eat heroin, it will be absorbed either as heroin itself or as morphine (some heroin breaks down to morphine in the stomach). What happens depends on the dose and the individual. The opiates will be absorbed slower than if the were injected, but the total length of time that the patient is exposed will be longer. Physchim62 15:29, 7 October 2005 (UTC)
Itunes Problem
I have a bit of an interesting situation regarding iTunes. I am attempting to share my music so that a friend can access it. However, we seem to be on different subnets, despite the fact that we are using the same ethernet jack to access the internet. Would it make a difference that I intially installed and started intunes using a different ethernet jack across campus? The initial network setup was also done across campus, perhaps if I change my subnet this will solve the problem? Thanks for any suggestions!
- How exactly are you using the "same" ethernet jack to access the internet? iTunes isn't designed to work via the internet anyway; rather, it's designed to work over local networks, so if you are both using the same router or something like that, things should be hunky-dory. Also, what are the models and capabilities of the computers you are using? Are they AirPort/802.11 capable? Garrett Albright 17:08, 5 October 2005 (UTC)
Poliosis / White Forelock
Hi This is not really a question but more of a request. I have performed some google searches to find a name for my husband's white tuft of hair above his forehead. I found Poliosis and White Forelock. I also found a list of dreadful diseases of which I'm fairly certain he has none. I then tried to find any information possible on Wikipedia and the search came up with zero. I'm just wondering if there are any personality traits (like extreme intelligence or other endowment) that might accompany this somewhat less common physical characteristic. I'd love it if anyone in-the-know could add this subject to your website.
thanks
There are many minor genetic physical traits that can occur by themselves or with several other physical anomalies. When they occur by themselves they have no hidden significance and cause no problems. When they occur with multiple other anomalies, some of those other problems can turn out to cause serious trouble. This combination of anomalies is usually referred to as a congenital syndrome. Other examples of minor physical anomalies that can be of no significance by themselves or can occur as part of a more serious syndrome are little pits in front of the ears, short broad thumbs or fingers, high-arched palate, and indented chest. Finally, there are no personality traits associated with this type of minor isolated anomaly because the only body part affected is that area of the scalp. alteripse 01:44, 5 October 2005 (UTC)
You can get a tuft of white hair by being scared shitless. Someone in my family once got that after she had fallen between railway tracks and had a train run over her. She was otherwise unharmed, but you can imagine her state of mind at the moment. But now I wonder how such a thing can happen. Does all the pigment get sucked out of the hair? And how does a scare cause that? DirkvdM 12:53, 6 October 2005 (UTC)
Having the pigment "sucked out" of hairs is as likely as having a sudden fright turn your nail polish from red to blue. Hairs already extruded from the hair follicles do not change color unless dyed, bleached, or oxidized. alteripse 03:16, 7 October 2005 (UTC)
- I agree that the color of existing hair won't change due to stress, but having a localized loss of pigment in future hair due to a stressful episode isn't impossible. I don't know if any studies have been done on this, but I can easily imagine that stress hormones like adrenalin could interact with pigment cells and cause them to shut down. Other causes could be genetic or environmental, such as Sun-bleaching (which actually could destroy the pigment in existing hair). StuRat 06:32, 9 October 2005 (UTC)
math
If you know the year month and date a person was born how can you quickly tell them what day their birthday will fall on this year? With no help from a calender thanks.
ABOUT BULLSEYE NETWORK VIRUS
When I use Internet Explorer, suddenly, a pop-up opens with the heading 'BULLSEYE NETWORK'. This pop-up appears when I open any website! Is that a virus that has attacked my computer or my Internet explorer? What should I do to get rid of that? Can anyone tell me more about this Virus?
- You have aquired a piece of adware. This is not technically a virus, but is almost certainly software you don't want on your computer. It is designed to be difficult to remove. I recommend you get a copy of Ad-Aware or any of its competitors and run it on your computer. The following Symantec page may be useful to you: [2].
- To prevent such infections in the future, please consider using a different browser, either Firefox or Opera. Internet Explorer is particularly prone to such infections.-gadfium 03:42, 5 October 2005 (UTC)
- Or better still, switch to Linux. That should shield you a whole lot more against viruses and the like. DirkvdM 12:55, 6 October 2005 (UTC)
Linux Lover 69.181.206.232 04:21, 10 October 2005 (UTC)
maths
Try starting in Mathematics --Borbrav 04:05, 5 October 2005 (UTC)
Random vector member?
In the standard template library for C++, is there any trivial way to get a random member of a vector (or map) safely? - RedWordSmith 04:57, 5 October 2005 (UTC)
- If I remember correctly (and I may not), isn't access to a random member of a vector O(1)? I believe vectors aren't linked list-backed types. Or is what you ask in the "safely" part? If so, what do you mean? Dysprosia 09:07, 5 October 2005 (UTC)
- User:RedWordSmith wants to choose a random element and to access it with a single command. I don't think that is possible. Masatran 10:37, 5 October 2005 (UTC)
- Yes, exactly. Any ideas on what the best way to do this using multiple commands? I've thought about shuffling the entire vector somehow a couple times and then taking an element from the top, but that can't be efficent no matter how it's done. - RedWordSmith 20:57, 5 October 2005 (UTC)
- C++ vectors are random access, implying O(1) access, thus these are most likely not linked-list like types. What is wrong with using operator[] on the vector? Dysprosia 22:47, 5 October 2005 (UTC)
- Maybe I'm missing something here, but wouldn't the following three step process work:
- Find out the number of elements in the vector (my C++ is very rusty, but isn't that the length method of the vector class)?
- Generate a random number with a pseudo-random number generator.
- Access the i'th object in the vector (either with operator[] or the at method, which is range-checked.
- The choice of which pseudorandom number generator to use depends on your application. If, for some reason, it is important that an attacker not be able to predict which element will be selected next based on the elements selected previously, you need a cryptographically secure pseudo-random number generator, otherwise any modern generator, including the one in your system library, will probably do (though I prefer to use the Mersenne twister for all my own simulation work because it's both good and fast).
- If you want a guarantee that you won't get repeated elements, then a shuffle is probably the best way to go. But here's a basic performance tip; if your objects are large, create a vector/array of pointers to them and shuffle the pointer array rather than the objects themselves.
- As to the interface, surely you could define a subclass of vector which adds a "ranelement" method that implements the procedure I've described above? --Robert Merkel 01:00, 6 October 2005 (UTC)
- OH. I get it now. Red wants to access an element at random. Yes, that solution is the one that first comes to mind. I don't think there's a simpler method... Dysprosia 09:31, 6 October 2005 (UTC)
- Thanks, I'll give it a try. For some reason I was under the impression that the element choosen by the random number generator might not exist; I guess I'm just too used to plain C. I think I also got thrown off track reading about nonstandard methods to get random samples at one point. - RedWordSmith 00:06, 7 October 2005 (UTC)
- Mod it with l if your RNG doesn't do generation within a certain range. Dysprosia 10:27, 7 October 2005 (UTC)
Anabolism and lifespan
Does a moderate level of body building and the associated muscle mass gain cause a decrease in life span? Lets assume that the person doing the body building and undergoing anabolism has a normal BMI and average build (that is, they are not overweight or underweight). Also assume that there are no steroids or supplements involved - only a small increase in protein rich foods being consumed. 205.188.117.71 04:59, 5 October 2005 (UTC)
No evidence is available for your specific question because such changes are never done in isolation from other factors that might change lifespan: healthier eating (e.g., reduced fat intake), reduction of unhealthy exposures (e.g., less time with secondhand smoke), etc. There is some evidence that in small mammals those who are allowed to eat less calories daily over most of their lifespan live a bit longer; this appears to be a phenomenon distinct from simple avoidance of obesity but we have no way to extrapolate this to people or to know exactly what the mechanism is. This topic of changing life span by changing daily living habits or eating habits is generally referred to as life extension and much has been published online and in the scientific literature but the quality ranges widely and much of what has been written about people is speculation, opinion, or marketing written to sell a product. Be skeptical. alteripse 10:36, 5 October 2005 (UTC)
The trick to a long life is to metabolize slowly. Like my turtle which I expect to out live me by about 100 years. I metabolize quickly because I like to have fun...unlike my turtle who just sits in the sun all day.--Eye 20:13, 5 October 2005 (UTC)
- Our Caloric restriction article is worth looking at as well. Capitalistroadster 04:55, 7 October 2005 (UTC)
Graying Hair
Why does hair turn gray or white as humans age?
- Our Hair article states: "Older people tend to develop gray hair (actually colorless) because the pigmentation in the hair gets lost and the hair becomes colorless. The age at which this occurs varies from person to person, but in general nearly everyone 75 years or older has gray hair, and in general men tend to become gray at younger ages than women." Capitalistroadster 07:19, 5 October 2005 (UTC)
- This answer is perilously close to Moliere's explanation that a sleeping potion worked "because of its dormitive properties." I am not sure how clearly we understand the process by which hair follicles stop having pigment. Is pigment generated by intracellular processes that are programmed to stop at a certain age? Are there separate cells at the base of hair follicles that add the pigment to a growing hair? What is the difference between hair follicle cells that grow a pigmented hair versus a non-pigmented hair? Are these hormone-dependent changes like puberty or menopause-- if so we have surprisingly little understanding of this type of change in early or middle adult life. Are these specific genetic responses to a certain duration and level of hormone exposure, like male pattern baldness? Interesting question. Anyone want to research an article on hair color? alteripse 10:52, 5 October 2005 (UTC) Well, guess what, the answer was already in our article:
- The change in hair color is caused by the gradual decrease of pigmentation that occurs when melanin ceases to be produced in the hair root, and new hairs grow in without pigment. Two genes appear to be responsible for the process of greying, Bcl2 and Mitf. The stem cells at the base of hair follicles are responsible for producing melanocytes, the cells that produce and store pigment in hair and skin. The death of the melanocyte stem cells cause hair to begin going grey. (Nishimura, et al., 2005)
Perhaps you didn't mean to get into the technical details of how pigmentation stops being produced, but were rather asking why, what evolutionary purpose does gray and white hair serve ? It may be that it serves no purpose, and is just a malfunction that isn't very harmful, so isn't selected very strongly againt. Another possibility is that visual age markers, like gray hair and wrinkles, are in some way helpful to the species. On the positive side, they may be ways to identify older people, who presumably have valuable knowledge and experience to offer, which may help the group survive. A more negative interpretation may be that this helps to identify people who are beyond their ideal fertility age, and thus should be avoided for younger more fertile mates. If either of these is a benefit to marking older people with gray and white hair, then evolution may actually select for this feature. Note that many other mammals share this trait with humans. StuRat 06:20, 9 October 2005 (UTC)
thrust agumentation
why a water nozzle is having a greater reaction when it is faced by a rigid wall very close to it rather than when it is faced in free air. --202.137.218.75 07:51, 5 October 2005 (UTC)Abhishek gupta, India
(formatted question and removed email - Mgm|(talk) 09:52, 5 October 2005 (UTC))
- You didn't say if the wall was right up against it or just close. When the nozzle is pressed right up against the wall the water can't get out as easily and allows the pressure to build up. This is also why a nozzle causes greater reaction, than when water comes straight out the end of the hose.
- Dysprosia is correct. When in the open air, the water pushes air out of the way, as the air can freely compress and move. As you approach the wall (which presumably does not compress or move), the water exerts a force on the wall, and the wall effects a reciprocal force on the water. At distance, the water tends to splatter into the air (per the initial condition). As the nozzle gets closer, more of the wall→water force is directed back toward the hose. Since water isn't compressible, this force transmits into the hose collectively. When the nozzle is directly adjacent to the wall, virtually all of the force affects the hose. — Lomn | Talk / RfC 14:36, 5 October 2005 (UTC)
Stabilizing the frequency of vibrations in a quartz crystal used in an oscillator circuit
Dear Wikipedia Volunteer, I am currently undertaking a research project. For this to be successful, it is important for me to know how to stabilize the frequency of vibrations of the quartz crystal used in an oscillator circuit. The quartz crystal in question is a 14.3183 MHz oscillator, but the output frequency is accurate only till 14.31 MHz (i.e. about 10 kHz). How can I stabilize the vibrations so as to get accurate output frequency in the order of tens of Hz? I would be highly obliged if you kindly post the answer to my query at your earliest convenience, or give me a few references in this regard. Thanking you, Yours sincerely, Saikat Das (removed e-mail address)
- Saikat, I don't know the details of your project, but if the crucial thing is that you need a high-precision clock signal, would something like [these] do the job? I found this by googling "precision oscillator"; lots of other relevant links turned up. --Robert Merkel 15:18, 5 October 2005 (UTC)
OpenDocument XML editor wanted
Is there any OpenDocument editor that can edit the XML elements directly? —Masatran 11:10, 5 October 2005 (UTC)
- If I'm not mistaken you can do that with any simple editor. At least that's the way to do it with html. Or do I misunderstand your question? DirkvdM 13:01, 6 October 2005 (UTC)
- List of text editors and XML#XML Editors. The problem is, that I don't think OpenOffice, KWord, etc. like to edit OGW as a set of textfiles, they prefer to interpret it. Ojw 13:41, 9 October 2005 (UTC)
Dance Pads Sales
Hello dear friends, Does anybody know how many dance pads (in units) are sold annually in the USA by manufacturer? Thank you Sincerely
Individual Generators and natural disasters
how long do individual generators last? Can generators communications be affected in natural disasters? should we be investing in new research to develop cheaper and better generators? Is the Department of Homeland Security in the US preparing for wide scale, long term power outages?
- Generators are more fuel-dependant than breakdown-prone, though such breakdowns can occur. On the whole, it depends entirely on the stockpiled fuel supply.
- I have no idea what generator communications are. Could you elaborate?
- Probably not. Again, fuel source is the main concern (and I'd consider a cold fusion generator more a problem of cold fusion research than generator research)
- I don't think there's any way the U.S. at large can prepare for wide scale long term loss of power. Check out some apocalyptic fiction (Alas, Babylon and Lucifer's Hammer are good examples) for thoughts on what such widespread devastation would mean for modern first-world society. In a nutshell, if a disaster of such magnitude strikes, basic survival will be far more important than maintaining the power grid. That said, reducing the dependancy on imported oil would alleviate a major choke point for the fuel supply. Nuclear energy (the most modular major power source) has been overwhelmingly unpopular since Three Mile Island and Chernobyl, however. — Lomn | Talk / RfC 14:27, 5 October 2005 (UTC)
- Generators will last as long as there is fuel for them and they stay in good working order. I presume you mean emergency type generators like you might find in the hardware store. There is ongoing research to find new ways to produce power (like fusion or solar power) but my opinion is the generators we have are just about as good as they can be expected to get without a technological advance.
- As far as your question about whether "Homeland Security" is prepared for anything except re-electing republicans, I think we got a pretty clear answer last month. alteripse 15:08, 5 October 2005 (UTC)
- To quote someone or other - "There is a major disjoint between people who think national security means keeping the nation safe, and those who think it means blowing shit up." Shimgray | talk | 20:04, 5 October 2005 (UTC)
Photosynthesis
Give an example of an experiment to find if photosynthesis has taken place inside a leaf.
Please answer this question now beacause I have a test and I could not understand this question. Thank you
- You could read photosynthesis, but we're not really in the business of doing other peoples' homework here. -- SCZenz 16:13, 5 October 2005 (UTC)
- I'm feeling nice, so I'll give you a hint.... What is a product of photosynthesis that you can test for? -(Fang)
- You mean like electrons? David D. (Talk) 22:23, 5 October 2005 (UTC)
- Electrons are not a product of photosynthesis. Imagine photosynthesis as an equation. What does photosynthesis produce? --Fastfission 17:00, 6 October 2005 (UTC)
- 2H20 + light (4 photons) --> O2 + 4H+ + 4e- is the first step of photosynthesis. Also known as the light reactions. I was trying to give a clue, although I admit it was somewhat cryptic. The traditional equation for photosynthesis ( 6CO2 + 6H20 + light --> 3O2 + glucose) is very misleading since it does not recognise that there are several independent reaction associated with carbon fixation. The first step does not involve the fixation of carbon it is all about converting light energy into chemical energy. The reduction of NADP to NADPH using the reducing potential of the electrons. As well as ATP from the movment of the electrons through the electron transport chain in the thylakoid membrane. David D. (Talk) 17:25, 6 October 2005 (UTC)
- Electrons are not a product of photosynthesis. Imagine photosynthesis as an equation. What does photosynthesis produce? --Fastfission 17:00, 6 October 2005 (UTC)
- You mean like electrons? David D. (Talk) 22:23, 5 October 2005 (UTC)
- I'm feeling nice, so I'll give you a hint.... What is a product of photosynthesis that you can test for? -(Fang)
Heroin
What happened to my ? on heroin when eaten in food? Thanks, Toni
We answered it. Read more closely above. alteripse 15:06, 5 October 2005 (UTC)
Internet Statistics
I am attempting to find some internet statistics:
- How many people currently use Windows 98 vs. Windows XP?
- How many people have dial-up vs. broadband?
- How many people have an 800 X 600 monitor vs. 1024 X 768 or larger?
Thanks,
<removed e-mail address>
- I'm not sure about the numbers, but if you want to know this because of some design job, I recommend you design with the Windows 98 dial-up 800x600 users in mind (at the very keast offer a low-bandwidth option for them). There's nothing more annoying than site, images or programs that are not designed for your system. - Mgm|(talk) 20:57, 5 October 2005 (UTC)
- If you buy stock in companies that sell this stuff, then you get their annual reports which have actual numbers of how many got sold that year. Some companies make their annual reports available to non-shareholders. So then you need to get them for every year since the products that interest you came out.
- There are also places that have already done this kind of research and published the results, Gartner Research for example ... use Google or some other search engine (there are scores if not hundreds to choose from) to find places that do Research, then search them for the kind of research reports you interested in ... I think Gartner Magic Squares would be very close to what you looking for.
- Gartner Magic Squares are charts of various types of products within some industry ... one dimension is all the stuff the products can do, another dimension is degree of market share the market leaders have, yet another thing shown is how good the stuff is relative to each other, with various vendors products plotted on this thing, accompanied by an article that goes into details about what is plotted on the graph.
How do plants and trees live in islands where their roots are in sea water?
Hello everybody,
I have always been wondering while seeing some nature tv programs or photos or etc that how come trees are able to live in such conditions as in islands where the soil is ssandy and permeable to sea water and these trees most probably have roots that are soaked in salty sea water. Apart from the fact that many trees, as far as I know, could not stand the salt in the sea water, their roots are also not able to breath oxygen, could they? As you see in many commersial photos or educational tv products there are islands where their jungles are only a few meters away from the sea water. How is that?
So please let me know how do these plants survive? Is their roots in sea water at all? It those are those roots adapted to these situations or their is some mgical thing happening there?
I hope i could have been able to explain my question as good as possible.
Thank you for your replies in advance.
Eqbal Vakilzadeh
- Plants, like other forms of life, are adapted to fit certian circumstances. Not all trees are the same.
- It is not just about adaptations. Obviously mangroves do live in brackish water. They have several adaptations to allow this. High quantities of salt in their cells that means water can move from the brackish water to the even saltier mangrove cells by osmosis. This would not be possible for regular trees as you suggest above. mangroves also have air tubes in their roots specifically to get the oxygen down to the tissues under water. You're right that hypoxia this is a very real problem for trees that live in standing water.
- With respect to the islands, the key is that the ground water can push out the sea water. This web site has a diagram and description [3]. Even trees at the edge of the island it is possible for them to get fresh water. David D. (Talk) 21:41, 5 October 2005 (UTC)
This is it. thanks for the info and the link. eqbal
Computing
differences between windows nt and windows 98
- Apart from the fact that they're both versions of Windows from Microsoft, nearly everything. The code bases and design rationales are entirely different, and that filters through the whole of both operating systems. Check out Windows NT and Windows 98 for more. — Lomn | Talk / RfC 18:04, 5 October 2005 (UTC)
manufacture of dimensions in nanometer range
How is the stylus tip made up of hard material like diamond which is used in surface roughness measurements manufactured to have a radius in the range of nanometers ?What is the procedure involved?
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Aggregated diamond nanorods have been made by a new method and there are more conventional methods such as Chemical vapor deposition. --JWSchmidt 03:22, 8 October 2005 (UTC)
Unknown Energy?
Would it be right to say that energy in its pure form is unknown to us? For instance I cannot see the light that passes across my field of view. It seems that we can touch, hear, and see energy but only when it is interacting with the matter of our own bodies, our eyes, hears, or skin and in doing so does the energy that triggers the reaction of our senses changes it form? If so would it not also be so that what ever device we construct to measure energy would have the effect of changing the energy which we try to measure? Could or does energy exist in a form unknown out side the world of matter that we exist in? --Eye 19:57, 5 October 2005 (UTC)
- Energy is a conserved quantity that is associated with ___location (potential energy), motion (kinetic energy), and with matter itself (see E=mc²). Possibly the best candidate for "pure energy" would be the photon, the massless light particle, and you are absolutely right that one only sees photons when they interact with the matter in your eyes (or, if they hit your skin, they can give you a sunburn). It is a principle of quantum mechanics that you cannot observe anything without changing it; this applies to energy in any form, regardless of the device you build. To answer your last question, dark matter and dark energy are two things whose affects we can observe in cosmology but whose nature remains unknown to us; they compose the vast majority of the energy of the universe. Hope that helps! -- SCZenz 20:09, 5 October 2005 (UTC)
Mmm...I like the dark energy bit.--Eye 22:06, 5 October 2005 (UTC)
- Better known as the Measurement problem. - Cobra Ky
(talk, contribs) 22:15, 5 October 2005 (UTC)
- Anything that exists outside the reality we live in can not be observed by us and therefore does not exist as far as we can (ever) tell. Dark matter and energy are theoretical solutions to problems in cosmology. One could say that they are observed indirectly, but then everything is observed indirectly. When I look at a table I really just register the light that is reflected by it. And I don't even see the light, but only register the effect it has in my eyes and brains. DirkvdM 13:54, 6 October 2005 (UTC)
water solubiliry in the body with homeostasis
How is water solubility used to maintain homeostasis in the body? What are four examples of this?
- It all depends on what points your lecturer made. Was there reding material set with this problem. it might be worth checking that first.David D. (Talk) 22:41, 5 October 2005 (UTC)
Freshwater Invertebrates and Marine Invertebrates
I am trying to find the basic information on what differentiates certain freshwater invertebrates with marine invertebrates. For example, there are several invertebrates (Crayfish, Jellyfish, snails, etc.) that live in either freshwater or marine/sea water, what differentiates them? Why can one species of crayfish live only in freshwater and not in saltwater? How is the freshwater crayfish different from the marine crayfish?
If anyone can help me to answer this, I would REALLY appreciate it! Thanks!
- Our Crayfish article states that in New Zealand "the name crayfish or cray, refers to a spiny lobster, and crayfish are called freshwater crays or koura, the Maori name for the animal." Is that what you are referring to?
Alternatively, I suspect that the Speciation article referring to the emergence of new species through Evolution and Natural Selection. Capitalistroadster 01:17, 6 October 2005 (UTC)
- The basic difference is physiological. The freshwater organisms are better at pumping excess water out of their bodies, thus maintaining the salinity of their cells, coelomic fluid or blood. WormRunner | Talk 02:57, 6 October 2005 (UTC)
DNA/Cloning
How much of a DNA sample is enough to make a clone of something? What is the best source of DNA in relation to cloning?
No one has successfully made a cloned animal with just a DNA sample to start with. alteripse 00:56, 6 October 2005 (UTC)
To make an actual clone of something, you'd need to replicate all of its DNA (or extract a full set). A full set of the DNA of any living thing is present in every one of its cells. You could also read Genetics, DNA, and Cloning --Borbrav 01:20, 6 October 2005 (UTC)
- In addition to the DNA you need the right environment, starting with the right cell (although I believe you don't necessarily need a cell of that specific species - something closely related would do). And then that cell needs a womb (natural or artificial) to grow in. DirkvdM 13:58, 6 October 2005 (UTC)
And you might want to try the article on Polymerase chain reaction to answer your "amount" question. --Michael 04:03, 10 October 2005 (UTC)
Computer languages
what is an atom in some computer languages?
- Take a look at Lisp atom, and also Prolog. There may be other meanings of the term in other programming languages.-gadfium 02:54, 6 October 2005 (UTC)
Killing Me Softfruit : Which food would kill you first?
Of all the things a person in a modern Western democracy might normally consume as part of a meal, which would kill with the lowest dosage? The test subject is to be fed on the test food alone and is allowed any quantity of water and time for comfort breaks. --bodnotbod 01:46, 6 October 2005 (UTC)
- My guess would be alcohol. — Laura Scudder | Talk 01:54, 6 October 2005 (UTC)
Oooh, fun game. Tricky though. For instance if you include trace amounts of things that we ingest but don't intend to and are not conscious of, the answer would be aflatoxins, other natural neurotoxins like botulinum toxin, or pesticides and other chemical contaminants. We certainly "might normally consume as part of a meal" trace amounts of these things, but it would take only mg amounts to kill us.
Now if you restrict your contest to things that we deliberately and knowingly ingest as food, then alcohol seems a pretty good choice if taken as a single dose (1-3 oz of pure ethanol can be fatal to an adult), but if spaced out it would require a much larger amount. Same for caffeine. However, your allowance for "any quantity of ... time for comfort breaks" would suggest we could stretch out the exposure. So it looks like you'd better impose more rules. alteripse 03:08, 6 October 2005 (UTC)
- I wonder if you could kill yourself by OD'ing on salt? --jpgordon∇∆∇∆ 03:59, 6 October 2005 (UTC)
Of course. You can OD on water or oxygen also. The amount of salt that would kill you if you had access to sufficient water and could take "comfort breaks" to unload some of it would be larger than the mg of caffeine that would be fatal. However it is not a bad suggestion if the contest limited you to a single dose you had to ingest in one sitting. alteripse 04:07, 6 October 2005 (UTC)
Well, a relatively small bite of most anything that can be lodged in the throat has taken down multitudes over the ages but I think I am cheating. Qaz (talk) 04:14, 6 October 2005 (UTC)
If you knew you had a food allergy- you could do it will a minimal amount of the relavant food stuff.--nixie 04:19, 6 October 2005 (UTC)
- Vinegar wouldn't do you too much good either under the test conditions. Salt would fairly quickly cause renal failure (or drowning, by the amount of water consumed - this has happened in France). Cooking oil might start dehydration by diarrhea, but probably wouldn't work as fast as the others. Anything infected with cholera would be pretty fatal, as would certain uncooked beans, but that must certainly be cheating! Physchim62 15:41, 7 October 2005 (UTC)
- Most of these seem rather unappetising. Except maybe the alcohol. How about a couple of pounds of green potatoes, nicely cooked in the means of your choice? Notinasnaid 17:41, 7 October 2005 (UTC)
- That's almost cheating, too, as you wouldn't normally eat it. Along similar lines I could propose what killed Christopher McCandless: potato seeds which he helpfully discovered become poisonous in August. But so far I think alcohol is the best bet so far as things you'd normally ingest and could get someone to down fast enough. — Laura Scudder | Talk 17:55, 7 October 2005 (UTC)
- A freshman died from water intoxication recently during a hazing incident at California State University, Chico. User:Zoe|(talk) 07:45, 9 October 2005 (UTC)
Neurotransmitter Receptor Unbinding
When neurotransmitters are released, they bind onto a receptor on the post-synaptic neuron, and open a ligand-gated channel. However, I can't find any details on how or if they 'unbind' so that this channel can reset, and the general mechanism of this occuring. Certainly, the pre-synaptic cell and enzymes have mechanisms to reduce the concentration of neurotransmitters in the cleft, but I don't see how this causes the neurotransmitter molecules to unbind and therefore allow the channel to be activated again. Any details on this mechanism or whether such a mechanism actually exists would be of great use. Thanks. --Lynto008 03:20, 6 October 2005 (UTC)
- You are reminding my of the most boring part of by biomed courses :) I just whipped out my copy of Human Physiology (Vander, Sherman, and Lucino).
- If memory serves, unbinding depends on the type of ion channel. [Ligands] "produce either an allosteric or covalent change in the shape of the channel protein. Such channels are termed "ligand-gated channels, and the ligands that influence them are often chemical messangers" (116). Those channels are often further subdivided. What turns the channels "off" depends on the type. It's often either the unbinding of the ligand, or a messanger lipid, or another enzyme ligand, 'etc. →Raul654 03:31, 6 October 2005 (UTC)
So when its said that the ligand 'binds' to the receptor, what is really meant is that it 'triggers' the receptor by changing it, rather than actually attaching? More like the ligand turns on a switch than acts like a key? Because the way that the article Neurotransmitters (and just about everything else i can find on the internet) puts it, "The neurotransmitters... bind to receptors.", which to me seems to imply that it attaches somehow and would remain on the channel triggering it until it is somehow cleaved off. I know that this seems a bit pedantic but to someone who is trying to grasp these concepts, it certainly makes a huge difference. Is it true that the ligands don't really 'bind' per se and that there is actually a distinction? If so, this needs to be mentioned somewhere in wikipedia. Thanks again. --Lynto008 07:50, 6 October 2005 (UTC)
- What you are asking is really not biology, but more physical chemistry ;)
- A ligand is, by defintion, something that chemically binds to something else. Neurotransmitters are ligands that bind *VERY WEAKLY* to receptors (ion-gated channels), meaning it takes very little energy to break such bonds. The process of binding causes the channel to change shape, allowing stuff to pass through it. However, the weak bonding means that it's very easy for the ligand to pop right back off - possibly even caused by thermal energy (remember, everything is vibrating very fast at the molecular level due to heat -- imagine trying to hold onto something slippery in the middle of an earthquake). →Raul654 08:00, 6 October 2005 (UTC)
Nevermind - I looked up allosteric. Means binding. Duh. --203.206.109.81 07:58, 6 October 2005 (UTC)
Technological trends in information systems
What are the key tehcnological trends that heighten ethical concerns?
I am taking "heighten ethical concerns" to mean "increase people's attention to the ethical aspects of their choice of behaviors." The key technological trends that allowed people to be aware of choices of behavior and to have the time energy and tools to think about ethics were were agriculture, hunting tools, food storage technology, and communication and recording technologies. If you mean something else by the phrase "heighten ethical concerns" please explain. alteripse 03:15, 6 October 2005 (UTC)
- You might also educate yourself about the US law commonly called Sarbanes Oxley which imposed accountability standards on a wide spectrum of corporate and other entities doing business in the USA, in the wake of the accounting scandals that led to some of the largest companies in the world going bankrupt. These new regulations also imposed new rules on the information technology aspects of those companies, non-profits, unions, etc. that some people label as being ethical standards, and others label as additional money making sources for the lawyers, in a nation that is by the lawyers, for the lawyers and of the lawyers, with all the other residents being to provide the income to the lawyers. AlMac|(talk) 04:59, 8 October 2005 (UTC)
longest ship in the world?
The best I can find is an entry in the middle of this section: A.P._Moller-Maersk_Group#1993_-_1999_:_bigger_and_bigger. -- SCZenz 03:39, 6 October 2005 (UTC)
- Seems to be that or the Queen Mary II. --jpgordon∇∆∇∆ 03:53, 6 October 2005 (UTC)
- Unless the QMII's length is severely rounded, the transport ship I linked to has it by 1.9 m. -- SCZenz 03:58, 6 October 2005 (UTC)
- Just a bit of trivia; the Great Eastern was built a century and a half before that but was almost 2/3 the size of these ships. Truly humungous for that time. DirkvdM 14:28, 6 October 2005 (UTC)
Queen Mary II is the longest cruise liner at 345 m LOA; Sovereign Mærsk is perhaps the longest container ship 346.9 m. But a number of supertankers are much bigger, for example, Knock Nevis, 458 m. Gdr 20:25, 6 October 2005 (UTC)
- Though it barely counts as a ship -- more like a storage facility these days! The article does a good job of describing Knock Nevis and its twisted history. --jpgordon∇∆∇∆ 21:54, 6 October 2005 (UTC)
Uranium 238 decay chain
Is the information listed in http://en.wikipedia.org/wiki/Decay_chain correct?
Should Uranium 238 decay into an alpha particle, Thorium 234 AND two electrons?
- Giving off an alpha particle, plus two electrons, would change reduce the number of nucleons by four and leave the charge unchanged. This would result in U-234, as the page says. So it's at least self-consistent. The decay you indicate has a charge imbalance, unless I misunderstand. -- SCZenz 03:56, 6 October 2005 (UTC)
- The alpha particle is a helium nucleus, which has two protons and two neutrons in it. Thus, the U-238 loses two protons, two electrons, and two neutrons, and so charge is balanced. --Borbrav 00:32, 7 October 2005 (UTC)
- Yes and no. The nuclear decay of U-238 is by loss of an alpha particle to give 234Th2−: the thorium nucleus is not sufficiently close to hold on to the two electrons it has inherited and these are lost to the environment. See also electron affinity. Physchim62 15:47, 7 October 2005 (UTC)
Atoms and molecules
- In the absence of a specific question, I would suggest our articles on Atom and Molecule. Capitalistroadster 04:23, 6 October 2005 (UTC)
Sun & planet gear & epicyclic gearing
Does anyone know the connections between the sun and planet gear and epicyclic gearing. I don't know whether the later is a 'new' name for the former or developed from it or if they are unrelated but share some terminology? Any help would be much appreciated. AllanHainey 07:52, 6 October 2005 (UTC)
Rules of significant figures involving addition.
The rule for rounding to significant figures for addition is to round to the least number of decimal places involved. However, if the example were 1.01 + 3. + 1.1 would the rounding go to 4 or to 4.1? AKA, does a figure with no decimals mean to round to no decimals, or is it the least after that?
This came up in class yesterday and I was just wondering what the specific rule for this was and any reasoning behind this. Thanks.
- That would depend wether that specific number with no decimals is an exact number or not. For example, if my journey from home to school took 1.75 km then I would travel 2 * 1.75 = 3.50 km from home to school and back. If I have a yard of 2m by 3.71m the total surface area would be 2 * 3.71 =
12m7m2. --R.Koot 14:26, 6 October 2005 (UTC)
- Ah, trick question! 1.01 + 3. + 1.1 = 5.11 (not 4.whatever). As to how that should be rounded off, I'm a bit rusty, but I assume that the fact that there is a dot behind the 3 means that it's not exactly 3, but you don't have the numbers behind the dot, so you can't use those of the other numbers, so the answer is 4. (with a dot). As to whether that should be rounded off before or after the calculation, I forgot, but in this case the answers are the same. DirkvdM 14:40, 6 October 2005 (UTC)
- Rounding for numbers of known higher precision should be done after calculations so as not to propagate rounding errors. Think of adding 2.7 4.6 2.55 and 3. Rounding before the addition causes the rounding errors to add getting the erroneus answer of 14, when it should be 13. It's a bigger deal with multiplication of course. - Taxman Talk 14:27, 7 October 2005 (UTC)
- And R.Koot should go get his tuition fees back. 2 * 3.71 = 12m ? And I'm not referring to the omission of the '²'. DirkvdM 14:40, 6 October 2005 (UTC)
- Uhhh... I don't even know what I meant there? --R.Koot 23:21, 6 October 2005 (UTC)
- Thanks, Dirk. THat answered my question.... And nice catch on the 3 + 1 + 1 = 5... Oops!
- Ah, trick question! 1.01 + 3. + 1.1 = 5.11 (not 4.whatever). As to how that should be rounded off, I'm a bit rusty, but I assume that the fact that there is a dot behind the 3 means that it's not exactly 3, but you don't have the numbers behind the dot, so you can't use those of the other numbers, so the answer is 4. (with a dot). As to whether that should be rounded off before or after the calculation, I forgot, but in this case the answers are the same. DirkvdM 14:40, 6 October 2005 (UTC)
- Whenever you add, you keep all and only the decimals which were known in all of the numbers you were adding. i.e. 2.45+3.891=6.34, not 6.341. --Borbrav 00:22, 7 October 2005 (UTC)
- Rounding rules have different schools of thought based on the context of what is being arithmeticed.
- Suppose the military needs to move a certain volume of men and equipment, and the math comes out that to do this, they need 11.2 army trucks, the answer is not 11 trucks but 12, because there are cases where you always round up. AlMac|(talk) 05:02, 8 October 2005 (UTC)
English name of pen&paper game
The game is popular among Russian students. The rules are described here. "Pests" is a code-name. It's called "клопы" (a kind of pest) or "тараканы" (roaches) in Russian. I hope someone knows how it's called in English. Grue 13:38, 6 October 2005 (UTC)
depersonalization
What is the original reference for the information contained on your website concerning depersonalization, particularly the information regarding suicide ( as well as the general information provided). I have seen this exact wording on several other websites, but no references for the information.
Thank you,
Donna McCleary
- You can contact the people who contributed to the article, each of them is listed in the article's edit history. The links in the article appear to be authorative on the subject, so you might want to visit those and ask the people there for reliable references too. - Mgm|(talk) 15:50, 6 October 2005 (UTC)
helium
where did the name helium come from?
- From Helium#History: "He and English chemist Edward Frankland named the element after the Greek word for the Sun god, Helios, and, assuming it was a metal, gave it an -ium ending (a mistake that was never corrected)." - Mgm|(talk) 15:52, 6 October 2005 (UTC)
Heroin In Food
Until this AM I could not understand why I am having so many problems with my? Now I do.The reason I was asking about info. on ingesting heroin in food,is because that is how our daughter,Shenel,was murdered.People do not eat heroin,so we can find no info.on Toxicological Findings.That is ALL this is about!The FACTS!Any & all we can possibly get.As far as I know,and I have researched alot of drug sites,nobody knows.We did find alot of very good info.here,so I thought maybe you could find the answer to our ?.I just wish you would of let me know there was a problem with our ? instead of just deleting it.We'd still appreciate an answer,if you can find one.Our hearts are broken and she left behind two children.Eric was 4 , and Alyssa was 5 weeks old.Someday,if we can,we want to be able to explain all of this to Eric.Alyssa is with the man who killed her mother,so we lost her too.The sites we have gone on in New Zeland and Australia,which have done alot of studies on heroin,have made us realize the U.S.has alot to learn.Because of their lack of knowledge,this man got away with murder.It happens more often than you would ever believe,and we are all paying the price.We would be so grateful if you can help us?If not, I will know when I come back and see I have once again been deleted.I do want to thank you for all the good info.you did provide us with and say good-bye for now. Toni
- Toni, I sympathise with your situation, talk about stressful. No one has deleted your questions. Your first post with replies is still here, but you need to scroll up a long way to find it. Likewise your second post is still present. Realise that new topics are being added to this pages rapidly. David D. (Talk) 18:28, 6 October 2005 (UTC)
Regarding Heads
There was some talk around here a few days ago regarding the possibility of head transplants. The general consensus seems to be that there is no real reason a head could not be transplanted onto a donor body and live, albeit as a quadriplegic. So the question that occurs to me is this: Is the classic sci-fi/horror staple of a severed head being kept alive, artifically, possible? What about the even more cliched "brain in a jar"? With an oxygenated/nutrient enriched blood supply, under strictly controlled hospital conditions, is there any reason why a human head could not be kept alive, other than ethical ones? Brian Schlosser42 18:32, 6 October 2005 (UTC)
- Should be fine in theory.
But very difficult in practice. Certainly well beyond the current state of the art. See the Wikipedia articles on head transplants and whole-body transplants. Gdr 20:00, 6 October 2005 (UTC)
- I'm not sure it would be that difficult in practice, certainly a non-trivial proposition, but given the success of primate head transplants, I would think that simply keeping a human (I presume that the questioner is talking about humans) head alive would be well within the current state of the art. The major obstacles to actually doing this would be ethical, not medical.
- Funny that only a brain transplant is also called a whole body transplant. The same could be said for a head transplant I'd say. Also funny that the article on the former nevertheless goes on to speak about tranplanting the brain to another body. The alternative name exists for a reason (if one assumes personality resides in the brain). DirkvdM 20:40, 6 October 2005 (UTC)
The success of Dr. White's head transplants is, I think, rather overstated by our article. In the best cases, the head survived for several hours and showed signs of consciousness. Gdr 20:45, 6 October 2005 (UTC)
word password recovery
There is a free or open source word password recovery program, but I have lost it - does anyone know it? Thanks!
- One program that is free for 30 days is Elcomsoft Advanced Office Password Recovery. I haven't tried it so I can't vouch for it, but it might get you out of immediate trouble. There are lots of other programs but this was the first I found which appears to have a fully functional demo available.-gadfium 03:05, 7 October 2005 (UTC)
Elements
What is the importance of Iron?
- Reading Iron would be a good start. It's the final end-product of nuclear fusion, and steel is made from it. I think that's enough hints to start your essay! ;) -- SCZenz 21:38, 6 October 2005 (UTC)
- Lets not give short shrift to its role in hemoglobin. There is also its role in that time... what was it called... oh yeah, it was the Iron Age. Qaz (talk) 06:25, 8 October 2005 (UTC)
- Iron is one of the few metals we know of affected by magnetic fields. Rob Church Talk | FAD 15:49, 9 October 2005 (UTC)
- If you don't use it your clothes end up wrinkled. DJ Clayworth 17:58, 7 October 2005 (UTC)
- Unless you have decent clothes that don't wrinkle. DirkvdM 09:32, 8 October 2005 (UTC)
- Or use a tumble dryer, and get them out quickly enough afterwards. Certain clothes can be hung to allow the wrinkles to fall out too. Rob Church Talk | FAD 15:49, 9 October 2005 (UTC)
- The problem with this approach is that the fallen wrinkles collect at the bottom of your closet. If you don't wear socks or slippers, the wrinkles can then be transferred to your skin. (Ironing avoids this problem; the high heat inactivates wrinkles, which can then be transferred back down the powerlines for safe permanent disposal by the electric company.) TenOfAllTrades(talk) 16:10, 9 October 2005 (UTC)
- Or use a tumble dryer, and get them out quickly enough afterwards. Certain clothes can be hung to allow the wrinkles to fall out too. Rob Church Talk | FAD 15:49, 9 October 2005 (UTC)
- Unless you have decent clothes that don't wrinkle. DirkvdM 09:32, 8 October 2005 (UTC)
Guys,guys, come on it's a serious question...without iron the wheels would fall off my truck...I wouldn't even have a truck...
Apparently this is another essay question (header added subsequently)
State two ways in which a singled-celled organism, such as an amoeba, and a human body cell are alike.
- Any number of properties in cell might suffice, but my two favorites are:
- If I were you, I would write your essay based on something else, though. ;) -- SCZenz 22:22, 6 October 2005 (UTC)
Biology
Plants produce cholorophyll to capture the energy from the suns ray's and take in carbon dioxide from the air, and water from the soil. What characteristic of living things does the show?
- Their tendency not to do their own homework. (LOL, great answer !)
- In seriousness, you should ask a more specific question. That describes lots of characteristics of living things; I suspect that only one of them, however, is on your vocabulary list for the week. RSpeer 22:23, 6 October 2005 (UTC)
- You might look at Life, in particular Life#A conventional definition. -- SCZenz 22:24, 6 October 2005 (UTC)
Adaptation?
Ears
What animals have ears on the sides of their body? ...rabbits on my bumper--Eye 20:28, 9 October 2005 (UTC) and What animals have ears on their antennae? ...flies on my windscreen--Eye 20:28, 9 October 2005 (UTC)
Smelling Extract
I am battling a stopped up nose and I once heard that smelling peppermint extract could break up the mucus. Does this work? Would sniffing the extract fumes kill brain cells? Could it get me high?
- Your brain cells are dying as we speak anyway, and I suspect wine would do more damage to them than peppermint. Why not try it and report back here?--inksT 04:47, 7 October 2005 (UTC)
- I suggest you visit a pharmacy, sometimes called a drug store (that sells legal drugs) and direct your question to the pharmacist there. Typically there are scores of different brand names of remedies, at very reasonable prices. AlMac|(talk) 05:07, 8 October 2005 (UTC)
Cough drops create substantial vapors, that will serve such a purpose, while you suck on them. I suggest a menthol-eucalytptis blend, that really does the trick. StuRat 05:34, 9 October 2005 (UTC)
One up each nostril should work --Eye 20:25, 9 October 2005 (UTC)
how do telescopes work?
- Optical telescopes use a series of lenses to magnify distant objects, the same way a microscope does. Other types of telescopes are a bit more compliated. →Raul654 04:23, 7 October 2005 (UTC)
- Our Telescope article should be of some assistance as should the articles on specific types of telescope listed at the bottom of the telescope article. Capitalistroadster 05:01, 7 October 2005 (UTC)
- Also, if you typed this query into google, your second hit would've been this page from HowStuffWorks.com which has some info which may help you if you find the Wikipedia article too difficult to understand. - Mgm|(talk) 16:31, 7 October 2005 (UTC)
Why do some noises cause goosebumps?
When someone scrapes their fingernails against a chalkboard, I get goosebumps. What is the reason in this?
- I'm not sure exactly why sound initiates goosebumps, but the reaction is vestigial. Back when humans had hair covering their bodies, the reaction which is technically called piloerection, was intended to make ourselves appear larger, much like a cat does today when they are frightened. My guess would be, that a scary sound also triggers this reaction (like for instance the roar of a lion). Hope that helps. - Cobra Ky (talk, contribs) 17:18, 7 October 2005 (UTC)
medical term
What is meant by 'osteophytic lipping'?
Rgds, --Ciesse 203 13:52, 7 October 2005 (UTC)
Osteophytes are small projections of new bone growth or thickening. Lipping is a description of an x ray appearance. We need more context to interpret this, or you can ask your doctor. alteripse 19:46, 7 October 2005 (UTC)
- I can actually answer this. They are indeed bony projections, usually found on the outer edges of articular surfaces of joints. Occurs in people exposed to heavy loads (eg. slave labourers) and elderly. Yay! My BSc in Anatomy was useful for something! This calls for a party!.....--inksT 02:46, 8 October 2005 (UTC)
How do protons(+) not repel eachother...and....
how do electrons(-) not stick together with protons(+)??
- For the first question, this is the strong interaction - it's effectively nonexistent at long distances, but over very small distances (like those inside an atomic nucleus) it's very powerfully attractive. This is more powerful than the electromagnetic force, so it holds them together. See atomic nucleus. Think of it this way - two positive poles of a magnet will strongly repel each other, but if you duct-tape them together they won't actually be able to break apart, because the tape is stronger than the magnetism.
- For the second question, think of them as orbiting the nucleus very fast - they're falling toward the atom, yes, but satellites are also always pulled towards the earth by gravity, and they don't land on the surface. This isn't a very accurate description, but you might find it helps make sense of the problem. Shimgray | talk | 14:48, 7 October 2005 (UTC)
- Two protons, with no neutrons present, actually do repel each other. The strong nuclear force only helps in a nucleus where neutrons are present also. By the way, these are great questions--they were central mysteries of physics for much of the early 20th century. -- SCZenz 15:35, 7 October 2005 (UTC)
- Also, remember that an electron is not a thing (like a little ball), but more like a wave, or ring of evergy around the nucleus. It has to remain at a specific distance in order to orbit around the nucleus, determined by it's wavelength. --Mary
A good question to ask is how do neutrons help keep protons together in cases where the absence of neutrons woudl cause the protons to repel each other? Next question is why are neutrons stable in the nucleus when protons are present, but decay into a hydrogen atom when alone?
- Those are also good questions.
- The answer to the first is that the strong force between the proton and neutron is stronger than either the proton-proton or neutron-neutron force, and is enough to bind a proton to a neutron. So you can think of a nucleus as being more bound by the proton-neutron attraction than anything else (although the other interactions contribute too, they wouldn't be enough by themselves).
- The answer to the second, I think, has to do with energy. A free neutron has more energy than its decay producs (e.g. a proton, an electron, and an antineutrino). But for most nuclei containing a neutron, the energy is actually lower as things are now than it would be if the decay happened. (Because of nucleus stability/bond strength issues in question 1.) Thus a free neutron decays, whereas neutrons in nuclei don't. Interestingly, nuclei with too many neutrons will have lower energy if a decay happens, and there the neutrons do undergo beta decay.
- Hope that helps! -- SCZenz 22:41, 7 October 2005 (UTC)
Perl or Python?
I'm a budding computer programmer with free time on my hands. Is it better (more useful / more marketable in the job market) to learn Perl or Python? Or something else? I currently know Java and Prolog. Thanks!
Mary
- It's a bit of a tossup. Perl and Python both do pretty much the same thing in about the same amount of code at about the same speed. The primary differences are that (1) Python is far, far easier easier to learn and to read (it's easy to read someone else's python code) while Perl is (as a colleague of mind humerously noted) a "write only language" (2) On the other hand, Perl has been around three times longer than Python, and is more entrenched in the market. So where the job market is concerned, Perl is probably more attractive from that perspective. →Raul654 22:48, 7 October 2005 (UTC)
- Python is fun. Perl is not. I'd go with the former. Garrett Albright 01:34, 8 October 2005 (UTC)
- Do a search for Perl and Python on a recruitment website and see which ones look most interesting. Perl jobs tend to be mostly ISPs (and spammers if you're evil). The mobile phone industry is starting to use Python apparently, and I agree that it's nicer to use than Perl. You can also play with Ruby, which is somewhere in the middle, or Lisp if you're a follower of Philip Greenspun and Paul Graham. Ojw 15:03, 8 October 2005 (UTC)
- Nonsense. How is Perl "not fun"? How do you quantify a language being "fun" anyway? Dysprosia 04:08, 9 October 2005 (UTC)
- Oh, I won't lie and say that I wasn't being subjective. But the fact remains that Perl has a much higher level of entry than any other major language out there; it's like you can't help but write obfuscated code. The OP said she already knows some other languages, so I'd bet she could pick up Python in a snap because it's quite easy to "read." Perl, not so much. And since productive programming is fun programming, she'd be able to start having fun in Python much sooner, I'd bet. Garrett Albright 08:10, 9 October 2005 (UTC)
- I doubt that. To do something in Perl requires the same basic knowledge to do the same in Python. Perl is quite easy to read too, if you write it in a certain way. (It's not that I'm trying to be Perl-partisan here, I'm not, I just feel that some criticism of Perl tends to be overrated.) Dysprosia 11:34, 9 October 2005 (UTC)
Why do men have nipples?
Ya, I said it! But I would seriously like to know. - Cobra Ky 
(talk, contribs) 17:21, 7 October 2005 (UTC)
- Men actually have complete breasts, not just nipples...they are just underdeveloped. --Phroziac(talk)
17:27, 7 October 2005 (UTC)
- Well, usually! Manboobs! — ceejayoz ★ .com 03:35, 9 October 2005 (UTC)
Why? - Cobra Ky (talk, contribs) 17:28, 7 October 2005 (UTC)
- I think sexual differentiation could answer some of your questions. Most male and female organs develop from the same undifferentiated fetal organs; they simply develop differently under the influence of hormones. Female hormones stimulate the development of breasts during puberty, so women's proto-breasts develop while men's don't. — Laura Scudder | Talk 18:13, 7 October 2005 (UTC)
- Stephen J. Gould's essay "Male Nipples and Clitoral Ripples" is a pretty good essay on the subject. I think it's in Bully for Brontosaurus. --Bob Mellish 18:20, 7 October 2005 (UTC)
The short answer is that there has been no biological reason to eliminate them. The genes for nipples are very ancient ones common to both sexes of all mammals and are not carried on the Y chromosome. The basic equipment of a nipple is biologically cheap. It is made operational when needed by hormone signals. A defect of nipple or breast development carries little reproductive penalty to a man but a strong reproductive penalty to the other 50% of the population, so nipples continue to be advantageous and evolutionarily conserved. An intelligent designer of course would not bother to design a male with them: this type of trait is far better explained by evolution than by any competing hypothesis. alteripse 19:43, 7 October 2005 (UTC)
- The biological reason to eliminate them is not strong enough to cause them to be eliminated, much like the appendix.
Thanks for the answers everyone. I believe I thoroughly understand now. The reference to intelligent design was quite interesting as well; another score for evolution theory. - Cobra Ky (talk, contribs) 23:05, 7 October 2005 (UTC)
- I think User:Alteripse is giving the field of intelligent design far too much credit by supposing it makes any testable claims about the nature of the designer. Gdr 13:12, 8 October 2005 (UTC)
Seems a lot of guys out there aren't using their bodies for what they were designed for. Nipples are sex organs, not just in women but also in men. They become aroused during sexual activity, and they can be sucked, licked, massaged, squeezed etc to enhance sexual activity. Try squeezing your nipples - if you don't get a nice feeling "down there" then maybe you need to practise a bit. JackofOz 01:19, 9 October 2005 (UTC)
- There is an interesting parallel in industry, where it is frequently cheaper to make everything the same, even if that means some "additional equipment" is included that was not "ordered". For example, circuit boards are often built with everything and then those options the customer doesn't want are burned off or otherwise disabled. It doesn't seem intuitive that this is efficent, but the cost of producing many different types of circuit boards apparently is more than the cost of destroying unwanted components. StuRat 05:12, 9 October 2005 (UTC)
Can Big Red gum cause permanent tongue damage?
If you cover your tongue with Big Red chewing gum and stick it out of your mouth for an extended period of time could it cause permanent damage?
- I am not sure what mechanism of harm is worrying you, but the surface of the tongue heals even faster than the surface of the skin. alteripse 19:44, 7 October 2005 (UTC)
- Really? I didn't knew that. Could you add what you know to tongue? ☢ Kieff | Talk 23:02, 7 October 2005 (UTC)
- It's just that the tongue and inside of the mouth are mucous membrane tissue. Although not as tough as epidermis, mucosal membranes have a blood supply that is more plentiful and closer to the surface and have a higher density of immune cells and are more resistant to wound infection. I suspect (off the top of my head) that there are higher densities of precursor cells and faster responses to injury in mucosal membrane compared to skin. In practical terms, this is why doctors in emergency rooms dont even bother to suture cuts in the inside of the mouth unless the tongue is almost severed (I am exaggerating only a bit here). alteripse 00:55, 8 October 2005 (UTC)
- Really? I didn't knew that. Could you add what you know to tongue? ☢ Kieff | Talk 23:02, 7 October 2005 (UTC)
- Yeah, probably not. It is unlikely any worse than burning one's tongue on very hot food -- it might hurt like an SOB for a few days but it heals pretty quick. --Fastfission 19:47, 7 October 2005 (UTC)
Frosty Question
On bright, still, autumn mornings just before the sun comes up I notice that the dew on my car windscreen is not frozen and then as the sun rises above the horizon the dew freezes. Is it possible that the solar wind passing the edge of the earth can cause the tempter to fall? I have noticed this happen on dozens of occasions over the years. Is there a link? --Eye 20:31, 7 October 2005 (UTC)
- The short answer to your question, I believe, is no. Sunlight isn't going to make anything on earth colder. Sadly, I have no idea what actually is going on. -- SCZenz 23:07, 7 October 2005 (UTC)
- If you think about it, the Earth doesn't start warming up from the Sun's rays untill well after sunrise. Thus, it could be just that the Earth is still cooling down, and the sunrise and freezing are unrelated. --Borbrav 04:01, 8 October 2005 (UTC)
- Dew freezing on the windscreen is a rare occurance in my part of the world, but I do know that in the middle of winter (in my ___location of Perth at least) the day's lowest temperature occurs about 20-30 minutes after sunrise so I wouldn't think it's a solar wind thing.--Commander Keane 06:11, 8 October 2005 (UTC)
- You spend your sunrises looking through a car window? Did you cheat on your wife and get kicked out of the house? :) I wish :-) --Eye 21:16, 8 October 2005 (UTC)
- But more seriously, I'm thinking about the influence of wind. I've often noticed that around sunset/rise the air suddenly becomes very still. Maybe a slight wind prevented the previous formation of frost.
- This makes me think of something else I've often noticed. When you boil water and then turn off the gas (if you use gas, that is - an electric stove works too slow for this) you suddenly get (more) steam. The reason for that, I assume, is that previously the hot air rising along the sides of the pot prevented the steam from forming. But if you turn off the gas, the water at first still boils and keeps on saturating the air. And the saturated air finally gets a chance to form steam. DirkvdM 18:01, 8 October 2005 (UTC)
Maybe frost isn’t the right word. What happens is that the dew freezes. The drop in temperature is very slight but enough and occurs after the sun has risen. A drop in the wind might be a more feasible answer but that is so with most frosty days. Maybe there is a weather person out there? --Eye 21:16, 8 October 2005 (UTC)
- Shortly after dawn the sunlight is coming in at such a shallow angle that it provides little heating, such that the thermal loss into space is greater. That means the temperature, on average, will continue to drop until the Sun gets to a more respectable angle. I said "on average", since local weather fronts can easily overwhelm this slight effect. StuRat 05:03, 9 October 2005 (UTC)
I had an interesting frost phenomenon on a car of mine. Frost would form on the hood then melt as the air warmed up, except for the areas of the hood with the cross supports under them, since they kept those parts of the hood cool a few minutes longer. The result was a frost X-ray of the hood ! StuRat 05:19, 9 October 2005 (UTC)
carbohydrate chart
How many grams of carbohydrate are in various common foods?
- Any site on the Atkins diet would keep such a list. You'd have to be more specific about which foods you're talking about if you want a useful answers from us. - Mgm|(talk) 22:12, 7 October 2005 (UTC)
Google carbohydrate content or carbohydrate list. You will find dozens of such lists, if not hundreds. alteripse 00:49, 8 October 2005 (UTC)
- This site provides a fairly comprehensive list of nutritional info for many foods:
carbon trading
WHAT IS THE SCOPE FOR INDIAN INDUSTRIES IN CARBON TRADING?
BY, SRUJANA FINAL YEAR B.E(CSE) PLEASE GIVE ME ANSWER TO MY MAIL-ID
- I've also seen this question in the Humanities reference desk, please only post it in one reference desk subsection. - Mgm|(talk) 08:15, 8 October 2005 (UTC)
- Srujana,
I have removed your e-mail as answers are not returned and you will start becoming more of a target for spam. Our Carbons emission trading article is a good start and our Economy of India article should give you some idea of the challenges. This release from the International Emissions Trading Association states that India has started trading [4]. These newspaper articles show that Biofuel and tree plantations are targets see [5] and [6].
Smoke
Is there a way to add a color to smoke? For example, adding a substance to a cigarette to colorize the smoke. Is this possible?
Sure, but most people think it would make cigarettes even more offensive. alteripse 12:31, 8 October 2005 (UTC)
Fireworks? DirkvdM 13:44, 8 October 2005 (UTC)
- See the "common pyrotechnic compounds" section of our fireworks article. Shantavira 16:56, 8 October 2005 (UTC)
- Note that you don't want to add most of those compounds to a cigarette. Doing so would tend to make them much more rapidly and efficiently deadly than they already are. Note as well that those compounds will give a coloured flame, but won't typically have an appreciable effect on the smoke. TenOfAllTrades(talk) 03:24, 9 October 2005 (UTC)
- There are some colored gases, like the purple of iodine or the green of chlorine, but those aren't the type of things you would want to inhale. StuRat 04:51, 9 October 2005 (UTC)
- The question mentions cigarette smoke only as an example, so the answer should not focus on that. And certainly not the act of smoking, because that can hardly be the intent, unless it's a machine that smokes for some research or something. What is the reason for the question? DirkvdM 13:06, 9 October 2005 (UTC)
- If you're asking because you want to film or photograph the smoke, then you could use coloured light to give the smoke a tint. Ojw 13:27, 9 October 2005 (UTC)
Generic Drugs
Is there a real difference between a generic and brand drug? I know they have to have the same active ingredient and have to be the same quality and everything, but then why do some doctors insist that a patient takes the brand and not the generic version? And why do so many people claim that the generic version of a drug do not work?
- Some time ago there was a discussion in Dutch politics if doctors should not be forbidden to prescribe those unnecessarily expensive drugs and if national health insurance should cover that (or only restitute the normal price). I don't know what the outcome was (or indeed how informed the politicians were). Doctors may receive money for pushing certain brands. And if the drug is sold by themselves, they will likely make a bigger profit from a more expensive drug (which is why that is not the way it works in the Netherlands). People in general may make such claims because with health one should not take risks and therefore the more expensive option should be chosen (as if that is ever any guarantee - especially when you don't really know what you're buying). But now I'm only guessing. It's comparable to the inflated prices of condoms and funerals - not the sort of thing with which people are inclined to complain about the price. Fyi, I pay about 0.10 € each for my condoms. Well, for that I need to buy a gros, but they keep for years and the point is that it's a good indication what a reasonable price would be. DirkvdM 13:58, 8 October 2005 (UTC)
Is there a difference? In a word, sometimes. Most of the time for most drugs and most people a generic will work as well at a lower price. For some drugs in some people the difference between a generic and brand name may more than trivial. The problem is that it is difficult to predict ahead of time. alteripse 05:51, 9 October 2005 (UTC)
Our Generic drug article states that they are bioequivalent to the brand drug. However, in 50% of cases there is no generic drug as the term of the patent has not expired. There may also be a newer drug which may be more effective but may also be more expensive. In short, it depends on the circumstances. Capitalistroadster 06:11, 9 October 2005 (UTC)
Postural Drop related to Scleroderma and Kidney Disease
Dear Wikipedia Volunteer,
I have just found out about your service in a Sydney newspaper and am very excited at its potential.
Having just searched in Wikipedia for "postural drop" no results were available, although I am aware that Google, at least, does provide some references.
I sincerely hope that some of your readers, or whoever, can throw some light on this serious and deilitating condition.
Kind Regards, Arthur Major --203.164.32.81 07:19, 8 October 2005 (UTC)
See orthostatic hypotension. alteripse 12:32, 8 October 2005 (UTC)
WBC Booster
Sorry if this is a repeat post, but I accidently posted this in another category.
I know there are drugs that some athletes take to increase their red blood cell count, but are there any drugs that increase the number of white blood cells?
- It's been answered at Wikipedia:Reference_desk/Miscellaneous#WBC Booster. - Mgm|(talk) 08:25, 8 October 2005 (UTC)
Coming out with generics
I was wondering why sometimes it takes so long for a generic drug to come out. I read something about the patents for allegra and I think flonase expiring and it was about a year ago I think, but generic versions are not available yet, why is this?
- Even when derived from the patented brand, generic drugs still need to do research to use the information to make a useful drug after which they need to have it tested and get all sorts of forms from government and health organizations. It's just a long, long process. - Mgm|(talk) 19:37, 8 October 2005 (UTC)
- It isn't always profitable to do so, either, especially if the brand name drug is fairly cheap already. — ceejayoz ★ .com 03:33, 9 October 2005 (UTC)
Muscles wasting
My cousins muscles are wasting away and the doctors told him he will eventually be in a wheelchair. The doctors also said there are no drugs currently that could help him and the only thing he could do is physical therepy. I was wondering if something like steroids would help him out? I know they are illegal and arent very safe or healthy, but would it work and stop or slow down the wasting of his muscles?
- Anabolic steroids are used sometimes for medical purposes, so I think that if they could help your cousin, his doctors would have thought of that too. Why not ask them about it? David Sneek 12:16, 8 October 2005 (UTC)
If your cousin has a muscular dystrophy there have been many clnical trials of anabolic steroids as well as glucocorticoids and growth hormone. They have not been found beneficial and sometimes have accelerated loss of strength. Search Medline for these terms if you want to find out for yourself. The muscular dystrophies are truly nasty diseases with few treatment options except support for most; I am sorry for your cousin. alteripse 12:30, 8 October 2005 (UTC)
- It sounds like Muscular dystrophy probably Duchenne muscular dystrophy to me. In answer to your question, this fact sheet from the Muscular Dystrophy campaign outlines that steroids are being used to treat muscular dystrophy see [7]. I have two young nephews with the disease and the good news is that research in a number of areas is delivering promising results. Wyeth are conducting human clinical trials of a treatment in adult muscular dystrophy see [8] According the National Institutes of Health, there are 13 clinical trials underway for various forms of muscular dystrohy see [9]. There have been positive outcomes in animal trials for gene therapy in recent times as well. Capitalistroadster 07:15, 9 October 2005 (UTC)
This is a nicer answer, with refs, than my gloomy one. Note that the "steroids being used to treat muscular dystrophy" in the MDA ref are glucocorticoids rather than anabolic steroids. The disease and both types of steroids have been well known for about 60 years. I didn't realize anyone was still running trials on glucocorticoids, but I didn't try to look it up. I hope some the cited research changes the traditionally pessimistic picture to which I alluded. alteripse 12:33, 9 October 2005 (UTC)
Pharmacy School
I'm interesting in applying for pharmacy school in the next few years, I was wondering how to increase my chances of getting in. I know good grades and a good PCAT score are important and also volunteering in a pharmacy, but what else can I do to increase my chances of getting in a good school?
Also, what questions do they ask at the interview? Thanks
Here is the same advice I would give if you asked about medical school or veterinary school. Concentrate on your grades, especially math and science. Most of the applicants whose grades and scores are within 10% of the average for last entering class will be offered admission, as will some of those whose grades and scores are below that. The principal purpose of the interview is identify unusual positive or negative characteristics that they cannot easily determine by the paper application, or cannot legally or publicly admit to using. Many of these characteristics are those you don't have control over. Another purpose of having an interview is to introduce a subjective element into the process so that taking one person over another with higher numbers can be justified.
If your grades and scores are at least average for the entering classes for that school, the prinicipal purpose of the in-person interview is to detect a disqualifying characteristic. This may differ widely depending on time, place, and local circumstances. One example might be race. Another might be an inability to hold a basic conversation and communicate. Another might be an appearance that suggests potential problems fitting in with the class and reflecting positively on the school. Another might be an extreme disability or an apparent mental illness. Another might be an indication that you would be unlikely to accept an offer of admission. In other words, the admission is yours to lose by the interview.
On the other hand, if your grades and scores are substantially below average for their usual entering class, the principal purpose of the interview is to look for an undetected asset. This may differ widely depending on time, place, and local circumstance. One example, especially in the US, may be race. Another might be an unusually impressive or attractive personal manner. Another might be to confirm other non-quantitative accomplishments. Another asset might be a family connection with the school or something to convince them you are more likely to accept and complete school than the other below-average candidates. Another might be wealth or political connection that could be of advantage to the school. In other words, a small number of students with well-below-average scores will win admission based on other things detected at the interview.
In other words the exact answers to the questions are not the point; it is the chance to detect other things. Work hard so you are in the first group and don't worry about the interview. alteripse 11:43, 8 October 2005 (UTC)
internet
- You found it. Any questions? Qaz (talk) 08:23, 8 October 2005 (UTC)
- By just getting here to ask the question, you must have used the internet. Like the person who asked what is operating system had to ahve used a computer to use the internet to get here to post the question. So we have people driving over the information superhighway who are not familiar with the terminology of the infrastructure involved, comparable to a person who drives a personal automobile, but does not know what a highway is. What is computer literacy coming to? AlMac|(talk) 15:41, 8 October 2005 (UTC)
Maths: Asymptotic Series
Can anyone help me solve this:
You are given a function
.
Find , and so that the formula
is true when .
Thank you.
- Here's a hint to help you with your homework: consider the Taylor series for . Gdr 14:00, 8 October 2005 (UTC)
The question makes no sense. How can and be in there both? Anyway,
, so
meaning , . 82.210.119.82 15:10, 8 October 2005 (UTC)
- See our article Big O notation for an explanation of little o notation, but essentially as . Little o notation is mostly used by mathematicians; a computer scientist would have used big O notation and written here (with much the same meaning).
- As for your derivation, you've got the Taylor series for wrong. Gdr 15:56, 8 October 2005 (UTC)
But if , how does change the thing — in what way is it different from ?
Chemistry: Small Mushroom Cloud?
I recall seeing a video of a (probably high school) chemistry lab. A teacher poured the contents of one beaker into the contents of another and it bubbled up and over the edge of the beaker and created a small mushroom cloud. What chemicals can be used to achieve something like this and what are the safety precautions surrounding it? Sorry, I can't find the video but thanks in advance. -Haon 14:48, 8 October 2005 (UTC)
- It would probably strongly depend on the conditions in the lab, including controlling drafts etc, so it might have just been luck. If you want the gas to fall below the top of the beaker, you'd want the gas to be cooler than the surrounding air, so probably good old dry ice in water would do the trick.
- So at a normal room temperature, dry ice combined with water would create a mushroom cloud? -Haon 19:43, 8 October 2005 (UTC)
- The main things needed for a visible mushroom cloud are:
- 1) The gas to rise must be much hotter than the ambient air temp.
- 2) The gas to rise must be visible.
- 3) The air must be relatively calm.
Q1werty
Q1werty was here--Q1werty was here 15:38, 8 October 2005 (UTC)
- You might be interested in the sandbox. AlMac|(talk) 15:43, 8 October 2005 (UTC)
L-alanine Vs. Beta-alanine
What is the difference between L-alanine and Beta-alanine?--65.33.222.71 15:45, 8 October 2005 (UTC)
- The position of the amino group on the carbon chain: see alanine and beta-alanine (although the latter doesn't have a structure diagram). Physchim62 17:25, 8 October 2005 (UTC)
timber joineries and defects of timber
can you please help with informative sites on timber joineries and defects of timber
thanking you amrita
- Amrita,
You might wish to check our Woodworking and Joinery articles for a start. Capitalistroadster 07:22, 9 October 2005 (UTC)
Gradient Invariance?
What is gradient invariance?
- Invariance means 'staying the same' and a gradient can mean lots of things, but usually means a gradual change or something that can be represented with an arrow. What's the context? DirkvdM 17:31, 8 October 2005 (UTC)
- I think it means that if is vector potential of a field , then so is the .
Compuer Science - locks and operating systems
In computer science and operating systems, what is a lock? Is it the same as a semaphore? --HappyCamper 17:45, 8 October 2005 (UTC)
- No, they're slightly different. A lock (also known as a mutex) is a logical construct -- you want sole access to a resource, so you "lock" it. Locks are usually implimented using semaphores, which are operating-system-supported atomic operations (and are fairly difficult to program with) →Raul654 17:48, 8 October 2005 (UTC)
- Locks are often set by application software without dependency on anything in the operating system. For example if the "in-use" field of a particular customer order is "on" that means some set of programs from one user is in middle of updating stuff in the order (which could span multiple files or tables), and all other programs in the application have to stay out until the user is completed.
- Program steps
- Is flag ok for me to access?
- if not, then message user about situation, and exit attempt
- if Ok to access, then set flag "in use" (by me)
- at end of access to that order, set flag "available" for others to mess with that order
- problem ... sometimes user access breaks (Windoze gets hung, communication link times out, someone kicks wall plug), the program ends abnormally, and the flag is never reset.
Biology: Benedicts and glucose
May I have the balanced symbol equation for the reduction of Benedict's solution by glucose, please?
- Wikipedia won't do your homework for you. See Chemical_equation#Balancing_Chemical_Equations to get started. — ceejayoz ★ .com 03:31, 9 October 2005 (UTC)
Polarization of Electrons
In physics we've just been learning about the wave-particle duality of electrons and it made me wonder - can the wave 'side' of an electron be polarized like light? And if not why not, is it not a transverse wave, is particle physics just too abstract at this level for us to understand or what? ;) --BigBlueFish 19:54, 8 October 2005 (UTC)
- Yes, electron beams can be polarized, and generally are in electron-positron colliders. It corresponds, if you're thinking about them as particles, to the spins all being aligned in one direction. (You can also think of polarized light as photons whose spins are aligned.) -- SCZenz 21:20, 8 October 2005 (UTC)
bees
bees can sting you. be careful. -Lethe | Talk 23:46, 8 October 2005 (UTC)
- Our Bee article may be a good place to start. Capitalistroadster 07:25, 9 October 2005 (UTC)
A Dense Question
I understand that hot air rises and cold air sinks. I also under stand that the same convection forces are at work in the earth and cause magma plumes to rise up to produce volcano’s. Where it all falls apart for me is that as gravity is at work on hot air in that when it cools it pulls the cold, dense air, back to the ground. How does this work in the earth when the force of gravity diminishes the closer you get to the centre?--Eye 21:40, 8 October 2005 (UTC)
- That's true, there is no gravity at the center of the Earth, and therefore no buoyant force to make the magma rise. But the magma that comes out of volcanos is not from the center of the Earth, but rather from the mantle, under the crust, where there is indeed gravity and buoancy.
-Lethe | Talk 23:33, 8 October 2005 (UTC)
- I think that you have a fundamental misunderstanding of gravity. Gravity does not diminish the closer you get to the center of the earth, infact, in increases very rapidly. The force of gravity is inversly proportional to the square of the distance, which mean that if you go halfway down to the center of the earth, gravity will not be not only stronger, but 4 times as strong! gkhan 00:12, 9 October 2005 (UTC)
- Sorry, gkhan, but that's all wrong. It's true that the Earth is sometimes modelled as a point mass with all the mass at the center. However, this model is only accurate when you are far from the center of the Earth, and preferably at the surface or above. However, if we insisted on using that poor approximation even when we were at the center of the Earth, the calcs would give us an infinite force of gravity, since our distance from the pt mass at the center would be zero. This would cause the Earth to collapse inward on itself into a black hole, leaving only those people behind who don't insist on using the pt-mass model when it isn't applicable, LOL. An accurate model would find the gravity vector between the person at the center of the Earth and each atom in the Earth, using the distance to each atom to determine the strength. All these vectors would then be added and would total zero, if an equal number of atoms were on each side. StuRat 04:18, 9 October 2005 (UTC)
- You are ofcourse right. It's been a few years, I apologise :P gkhan 10:08, 9 October 2005 (UTC)
- No prob, glad to help you shake off some of the rust on your physics memory. StuRat 16:10, 9 October 2005 (UTC)
- Suppose we are walking along the inside of a hollowed out asteroid that is in perfect mass balance, not spinning, The total mass under foot is tiny compared to the rest of the mass ... the center of gravity is to be floating in the middle of the hollowed out space.
- But center of Earth is different matter. Gravity has crushed the material of which the Earth is made to high density near center of earth. It is not hollowed out. AlMac|(talk) 02:44, 9 October 2005 (UTC)
- It would be more correct to say the forces of gravity would be balanced at the center of the Earth, hence there is no NET gravitational force. So, indeed, a person in the center of the Earth would be weightless. However, the immense pressure from all the material is believed to make the core of the Earth solid. Only the molten mantle between the core and the crust experiences convection, and, as noted previously, there is still considerable gravity at the mantle. StuRat 04:04, 9 October 2005 (UTC)
That’s a better way of putting it …there is no net gravitational force at the centre of the earth…which I presumes means that the mass of the earth above the point of centre pulls up in all directions causing the illusion of weightlessness of any object the happens to occupy the earths centre. Mmm…anti-gravity? :-) The force of gravity must exist then, like a crust around an object with mass like the earth. The maximum pressure must be exerted from near the surface and weaken towards the middle as the increase of mass above a given point pulls up on the mass below reducing the pressure. There should then be a neutral point be where the mass above a certain point would equal the mass below. A sort of gravitational boundary layer and this point would be determined by mass not size, i.e. that point would not be equal distance from surface to centre. Would this be where the iron core begins, and if so could the iron core be colder than people expect if the pressure on it is weakened by lower gravitational forces? --Eye 19:49, 9 October 2005 (UTC)
Quote about solipsism involving Bertrand Russell
On the page Talk:Solipsism there is mention of a quote I've been looking for for some time. I recall quite clearly reading just a few months back about a telegram that a female logician sent to Bertrand Russell that said something very like "Have converted to solipsism. Am enjoying it immensely. Don't understand why more people don't do the same." Unfortunately, I can't find this on Google, Wikipedia, or any books I have in the house. Can anyone confirm/deny? George
- I typed "betrand russell" solipsism into google and found this:
- Bertrand Russell was giving a lesson on solipsism to a lay audience, and a woman got up and said she was delighted to hear Bertrand Russell say he was a solipsist; she was one too, and she wished there were more of us. - Beyond Reductionism
- -- W. H. Thorpe
- was that it? -Lethe | Talk 23:29, 8 October 2005 (UTC)
- That's the thing. I can find references like that - to a layperson saying something dumb - but I have the clearest memory of reading about it in the joke telegram context. I do thank you for your help, though. George 00:38, 10 October 2005 (UTC)
limits in topology versus limits in category theory
Is there a way that you can interpret the limit of a sequence in a topological space as a limit of some appropriate functor between some categories? -Lethe | Talk 23:16, 8 October 2005 (UTC)
Identifying some fish and seaweed species
It would be great if someone could tell me what species some or all of the following are:
All were caught/picked off the coast of central Algeria. - Boualem 00:12, 9 October 2005 (UTC)
Genotypes
Here is the situation: A brown-eyed man whose father was brwn-eyed and mother was blue eyed married a woman whose father and mother were both brown-eyed. The couple has a blue-eyed son.
For which of the individuals mentioned can you be sure of the genotypes?
What are their genotypes? What genotypes are possible for the others?
Thank you for your time in advance
- Well I'll get you started on your homework! The trait for blue eyes in humans is recessive, so any blue eyed-person must be bb in genotype. Brown-eyed people can be homozygous or heterozygous for the dominant gene B. Take it from there! Physchim62 00:41, 9 October 2005 (UTC)
Alcohol
Why is alcohol so fattening? ♥purplefeltangel (talk) ♥ (contribs) 03:18, 9 October 2005 (UTC)
- It isn't. Non-alcoholic beer is just as fattening as alcoholic beer, for example - it is the other stuff in the drink. Lots of carbohydrates in beer. — ceejayoz ★ .com 03:29, 9 October 2005 (UTC)
- I might want to add a proviso to the remark above. Alcohol does have appreciable caloric content all by itself, but the total calorie content depends quite a bit on the beverage. Vodka is essentially pure alcohol (~40%) and water; it will run you about 65 calories per fluid ounce. Beer depends somewhat on how it is brewed. Stouts like Guinness get only about a quarter of their calories from carbohydrates; most of the rest is from alcohol. Sweeter lagers can draw up to about half of their calories from carbohydrates—they contain more sugar. Irish Creams like Bailey's are loaded with sugar and cream; only about a third of the calories are from alcohol, with the balance being from fat and carbohydrates. TenOfAllTrades(talk) 04:34, 9 October 2005 (UTC)
(after edit conflict)
- In virtually all plants and animals, glucose is transformed into energy in three steps: glycolysis, the citric acid cycle and oxidative phosphorylation. Yeast cells produce alcohol from glucose when there is little or no oxygen: they only use glycolysis to do this, and gain much less energy as a result, only 6% of the energy released by the three steps together. When the alcohol is consumed by another animal, it is broken down by the citric acid cycle and oxidative phosphorylation: the animal which consumes the alcohol is gaining the energy which the yeast could not obtain from the sugar, ie the other 94%. Hence drinking alcoholic drinks is almost as fattening as drinking sugar solutions... Physchim62 03:37, 9 October 2005 (UTC)
- Um, can you explain that in plain English please? ♥purplefeltangel (talk) ♥ (contribs) 03:43, 9 October 2005 (UTC)
- Sure, the body converts alcohol into sugar, so it's just like you drank a glass full of sugar-water, which would also be fattening. StuRat 03:53, 9 October 2005 (UTC)
- When turn sugar into carbon dioxide and water, you release 36 "units" of energy. When the yeast turns sugar into alcohol, it only releases 2 "units" of energy. When you drink the alcohol, your body releases the other 34 "units" that were present in the sugar. The Calories in our food are also measures of the energy released by our body when we digest the food: if we release more energy than we need, we store it as fat.... So alcohol contains almost as much energy as sugar, even if it doesn't taste sweet, and so is at least as likely to make us put on weight. Is that any better for you? Physchim62 03:51, 9 October 2005 (UTC)
Or, to put it another way. The yeast, being suck in an environment with no oxygen (by our design since we want the alcohol) relies on this trick where they can get a tiny amount of energy by doing a metabolism that results in alcohol as its end product. They do this because a little energy is better than starving to death. Later, we drink the stuff and we are able to extract the rest of the energy that the yeast was not able to get to. Since the yeast gets only about 6% of the potential, it is a good way to fatten oneself up. Qaz (talk) 04:00, 9 October 2005 (UTC)
Thank you. ^__^ ♥purplefeltangel (talk) ♥ (contribs) 05:08, 9 October 2005 (UTC)
- I seem to remember learning in 9th grade health class that when you're drunk, your metabolism slows and converts existing stores to fat at a higher rate. This might also contribute. -Lethe | Talk 05:10, 9 October 2005 (UTC)
Tests for Lymes Disease strain idenification
I am looking for the name of a test for strain idenification to idenifty where I got Lymnes. Can you help with this test name?
Thanks, 04:52, 9 October 2005 (UTC)65.7.78.21
- Our Lyme disease articles that the two serological tests for that disease are the Western blot and the ELISA test but neither tests are reliable indicators. Polymerase chain reaction tests are used but can show false-negatives. I would speak to your doctor about tests. Capitalistroadster 07:35, 9 October 2005 (UTC)
Excel problem
I accidentally did something to my excel options (I have no idea how) and now when I press the up/down/left/right arrows on my keyboard, the view scroll as opposed to what normally happens, which is the current cell moving. Does anyone know how to change the settings back. The version is Excel 2002. Thank you :-) Akamad 04:54, 9 October 2005 (UTC)
- Sounds like you have Scroll Lock turned on, IIRC. I don't have Excel handy to verify that though. — File:Ontario trillium sig.pngmendel ☎ 04:59, 9 October 2005 (UTC)
- mendel is right, I just tested it out. Turn scroll lock off to fix.--inksT 05:00, 9 October 2005 (UTC)
- Thanks all. That did the trick. Akamad 05:01, 9 October 2005 (UTC)
Swarovski Crystal vs Teeth
Just a question. I recently bought my girlfriend a little expensive lump of Swarovski Crystal carved into the shape of a rabbit. If we get a real rabbit, put the crystal into it's cage, and the rabbit chews on the crystal, will the crystal be scratched? I'm thinking Silicates vs Calcium compounds, but have no idea of the answer. Any thoughts appreciated. :) --inksT 05:03, 9 October 2005 (UTC)
- Looking at the Mohs_scale_of_mineral_hardness we see that glass has a hardness of 6 or 7. Hydroxylapatite, the main constituent of enamel, has a hardness of 5. The rabbit, however, could break the glass with a sudden bite rather than slow scratching. --Borbrav 05:38, 9 October 2005 (UTC)
- Indeed. Many people do not realize for example that although diamonds resist scratching better than any other common material, they are nonetheless vulnerable to breaking by the application of surprisingly little force. It is a good thing too or they would be much harder to cut into pleasing shapes for our Bling Bling. Qaz (talk) 05:42, 9 October 2005 (UTC)
- Thanks guys :) --inksT 07:43, 9 October 2005 (UTC)
- Indeed. Many people do not realize for example that although diamonds resist scratching better than any other common material, they are nonetheless vulnerable to breaking by the application of surprisingly little force. It is a good thing too or they would be much harder to cut into pleasing shapes for our Bling Bling. Qaz (talk) 05:42, 9 October 2005 (UTC)
general question
what is the reason for ice vessels are not licked?
- Because your tongue would freeze to the side. Gdr 11:41, 9 October 2005 (UTC)
- This usually only applies to materials with high themal conductivity, like metal. Materials with low themal conductivity, like styrofoam, could be very cold before licking them would freeze your tongue to them. StuRat 17:00, 9 October 2005 (UTC)
Seed Law
What is seed law?
- In what context do you mean seed? Could you provide a little more information so that someone can answer you more specifically? Then again, a search for "seed law" returned a considerable number of hits, quite a few of which appear to be related to civil law in the United States. Rob Church Talk | FAD 16:06, 9 October 2005 (UTC)
Stomach acid
I read in my biology book that stomach acid is supposed to kill bacteria, then why do people get food poisoning if the acid is supposed to destroy all bacteria?
- Because the bacteria can spread to all sorts of places before they even reach the stomach. - Mgm|(talk) 11:29, 9 October 2005 (UTC)
There are several ways this can happen:
- Some kinds of food poisoning are caused by exotoxins, poisonous substances excreted by bacteria before you eat them, for example botulin produced by Clostridium botulinum.
- Some bacteria, for example Staphylococcus aureus, produce toxins in the stomach before they are killed by stomach acid; these toxins are absorbed by the intestine.
- Some other bacteria have mechanisms that allow them to survive the acidic environment of the stomach. Escherichia coli can survive for several hours at pH 2, long enough to pass through the stomach. Some Salmonella species attach themselves to food particles and thus get some protection from the acid.
- Helicobacter pylori can survive indefinitely in the stomach (causing peptic ulcers). It survives by screwing itself into the stomach wall and excreting urease, which partially neutralizes the acid in a small region surrounding the bacterium.
Gdr 11:53, 9 October 2005 (UTC)
Quotation Marks in Word
How should I force my MS Word to show “” as quot. marks instead of »« when Smart Quotes option is turned on?
- Probably need to set it to English rather than French somewhere... either for the whole program, or for the text-style you're using (and don't forget: if you copy/paste anything with those quotes onto web-pages/wikipedia, then they will appear as invalid characters) Ojw 13:11, 9 October 2005 (UTC)
- Whenever I switch between language keyboards I find this to be a persistent problem. For example, my main keyboard is in English, so when I start a document it does the correct "English" style smartquotes. However if at any point I switch to another language (in this case, Russian), suddenly I get only Russian smartquotes (as you have above) even after I switch back to the English keyboard. It's very irritating and I couldn't find any way around it, so I just disabled Smart Quotes completely. --Fastfission 14:48, 9 October 2005 (UTC)
- I used to work in a computer lab where Word would do stuff like this often. I know there is a "Select Language" function somewhere in Word that will let you switch it back to English, but I can't recall how to access it. Try searching Word's help files for "language." Garrett Albright 15:58, 9 October 2005 (UTC)
Skin Breathing?
According to the Bond Film Goldfinger, painting someone with Gold kills them by stopping their skin breathing. Surely, if this was true, you would suffocate every time you went swimming? smurrayinchester(User), (Talk) 12:52, 9 October 2005 (UTC)
- On the one hand, yes, the Bond film is nonsense. On the other hand, there is a lot of oxygen suspended in water... Shimgray | talk | 13:30, 9 October 2005 (UTC)
- Humans don't have gills, so this oxygen is largely useless to us. Rob Church Talk | FAD 16:07, 9 October 2005 (UTC)
If the paint were thick enough to interfere with sweating, then it might lead to hyperthermia (heat stroke). Gdr 15:26, 9 October 2005 (UTC)
- Yes, it interferes with sweating and may cause
hypothermiahyperthermia, but under controlled situations it's hardly lethal as proven by the MythBusters. There's also a urban legend that the lady playing the gold-painted secretary died during filming. While it was quite uncomfortable she lived to do at least six more films and was available for a short interview with the MythBusters to show this particular legend was nonsense and she was still very much alive. - Mgm|(talk) 17:53, 9 October 2005 (UTC) - Snopes has a good write-up. --jpgordon∇∆∇∆ 17:54, 9 October 2005 (UTC)
The other question I have is 'If Gold is so expensive, would painting her with a pot of matte emulsion from B&Q be as effective as well as much much cheaper', but I guess he just wanted to show off. smurrayinchester(User), (Talk) 20:00, 9 October 2005 (UTC)
How to calculate reliability
Reliability is a qualitative property, not a quantitative value, so it can't be directly calculated. What are you trying to find the reliability of? Depending upon the type of the information/source, you may need to choose from a number of methods. Rob Church Talk | FAD 16:10, 9 October 2005 (UTC)
- No, there are plenty of quantitative measures of reliability (in one of its senses): see failure rate for a discussion. Gdr 16:51, 9 October 2005 (UTC)
- One can use the historical reliability of a product to estimate future reliability, but this is somewhat limited by constant changes to the product line. Defects may be repaired, which may increase reliability, while new features may be added, which tend to decrease reliability.
- In some cases, more direct ways to estimate the life of a product are available. For example, tires have a rated life (in km/miles) based on how quickly the rubber is expected to wear away with normal use. This type of estimate may be better for a new product, with no historical track record.
Reliability of what? A measurement? In a laboratory or something like a survey? If you speak of calculation that suggests you mean something scientific. But even then there are loads of things that can be (un)reliable. DirkvdM 17:19, 9 October 2005 (UTC)
Gravitational force as caused by the electromagnetic force
A few years ago, I tried to explain gravitational force as caused by the electromagnetic force. I got a force proportional to distance to-the-power minus six (instead of the required minus two). Will the derivation be of any use in making a Unified field theory? —Masatran 14:37, 9 October 2005 (UTC)
- The unification of gravity and electromagnetism has been tried before; see Kaluza-Klein theory. The results proved to be less than satisfactory, in the end, but they might be part of the solution what has turned out to be an exceedingly difficult problem. -- SCZenz 17:24, 9 October 2005 (UTC)
Converting image files
I have a Windows 98 computer. In Windows Explorer, is it possible to convert Microsoft Word files to other file types, and if so, how? HyperHobbes 15:53, 9 October 2005 (UTC)
- In general, to convert files from one format to another, open them with an application which can read them (Microsoft Word, in your case), then either do a File + Save As or a File + Export and select the type of output file desired. StuRat 17:28, 9 October 2005 (UTC)
How do I enable BitTorrent in Opera 8.5?
Does Opera 8.5 have BitTorrent disabled, or is it included at all? --pile0nadestalk | contribs 16:46, 9 October 2005 (UTC)
- The BitTorrent support was disabled on the final release of 8.5, but it's functional on the 8.10 tp2 release. See [10] ☢ Kieff | Talk 20:29, 9 October 2005 (UTC)
- I already tried this one but it has ads. Is 8.10 TP2 newer than 8.5? --pile0nadestalk | contribs 22:07, 9 October 2005 (UTC)
- Get Firefox! ♥purplefeltangel (talk) ♥ (contribs) 20:59, 9 October 2005 (UTC)
- Firefox doesn't support integrated BitTorrent at all, and probably won't for a long time. I'm using it now anyway though. --pile0nadestalk | contribs 22:07, 9 October 2005 (UTC)
- Sorry, I just hate Opera. :D ♥purplefeltangel (talk) ♥ (contribs) 23:23, 9 October 2005 (UTC)
- Firefox doesn't support integrated BitTorrent at all, and probably won't for a long time. I'm using it now anyway though. --pile0nadestalk | contribs 22:07, 9 October 2005 (UTC)
sending/receiving faxes online
Hi I was wondering if there was a free service or a very cheap one that would enable me to send a receive faxes online. I would prefer something that would let me goto "file" and then "print" and let me send a fax that way, similar to printing, but would ask me what phone number I would like to send it to. Something similar to efax.com. I used to use that, but now they want money.
Thanks
- You can send (but not receive) for free via The Phone Company if the number you want to send to is covered by them. It works via email or their web site, not by "printing" the fax to them, but it is free. -- AJR | Talk 22:46, 9 October 2005 (UTC)
energy from the seatemperature
I recently heard that an average hurricane unleashes an amount of energy equal to five times the worldwide annual energy consumption of humans (still can't believe it - did I misunderstand?). I understand that that energy comes from the temperature difference between the water and the air. So naturally I thought if this energy could be harnessed. There are two obvious advantages, one being the energy source and the other being the prevention of hurricanes. The Ocean thermal energy conversion article is about temperature differences between different parts of the water, which is something different (or is it really?). Would something like this be plausible? DirkvdM 18:12, 9 October 2005 (UTC)
- I've thought about this topic myself. There is a great potential there, but actually developing an efficient mechanism to exchange heat between the air and water is quite a difficult problem. The main issue is that the temp diff is so gradual and spread out over such a wide area. If we had a thousand degree temp differential of two dense fluids right next to each other, it would be easy to generate energy from this, but a 5 degree difference over two fluids (one of which is a sparse gas) more distant from each other is another matter. But, if you can think of such a device, your fortune will be made ! StuRat 20:36, 9 October 2005 (UTC)
- The surface water could also be cooled by using cooler water from below the area which receives most of the thermal energy from the Sun, but this is also impractical under today's technology. Perhaps instead of waiting until the water is over-warmed, a more proactive approach is in order. Large areas of the ocean could be covered by solar collection panels, to prevent the water from becoming warm, but the low efficiency and high cost of solar cells makes this scheme impractical, too. A newer technology, like genetically engineered microbes that live in seawater tanks, extract sunlight energy by photosynthesis, and release methane gas as a waste product (which we would harness for energy). might be a better way to go. StuRat 21:08, 9 October 2005 (UTC)
GASES
HELLO JUST GOT A QUICK QUESTION ABOUT GASES, WHAT GAS DISSOLVES IN WATER AND WHY82.26.64.128 18:55, 9 October 2005 (UTC)
- Lots of gases dissolve in water. Carbon Dioxide for example. But don't ask homework questions here and turn off your CAPS LOCK. smurrayinchester(User), (Talk) 19:58, 9 October 2005 (UTC)
what is the SI unit used to measure time?
You'll be wanting to look at our article on SI. TenOfAllTrades(talk) 21:30, 9 October 2005 (UTC)
also Time#Present day standards --JWSchmidt 21:32, 9 October 2005 (UTC)
- It will only take you a second to find the answer there. StuRat 21:38, 9 October 2005 (UTC)
Is it just me or is Mother Nature really pissed off?
- Three hurricanes went across Florida last year.
- Mt. St. Helens threatened to erupt.
- Thousands were killed by the Indian Ocean earthquake and subsequent tsunamis.
- Hurricanes Katrina and Rita tore up the Southern U.S. and areas south of that.
- A couple thousand people were killed in Guatemala due to a mudslide because of Hurricane Stan. They'll probably declare one town a mass grave since the inhabitants are under 40' of mud.
- And then there's the earthquake that hit Pakistan/India/Afghanistan with 20,000+ dead there too.
- I think I'm forgetting something from last year but I can't recall just what.
So, is it just me or does this seem like a lot of death, destruction, and mayhem caused by natural disasters for just two years? Can anyone point out another relatively short period of time where a series of events have taken place that have done similar damage? I realize that The Black Plague or possibly the devestation of Pompeii killed more but they had just one root cause. These events have had different root causes and have been more spread out. Or if I'm being naive, just let me know... :) Dismas|(talk) 05:42, 10 October 2005 (UTC)
The exponential growth of global warming contributes to many of these disasters one way or another. --Ballchef 06:21, 10 October 2005 (UTC)
Pharmacy Compounding
Is there a free web site that has compounding information and recepies?