Wikipedia:Reference desk/Archives/Science/2006 July 8

How was metal mined in the middle ages?
I mean, I know they didn't have the technology to mine massive amounts. Where were metal deposits found and how were they mined? Much help appreciated! 162.40.192.43 02:48, 8 July 2006 (UTC)


 * We have a few articles that may be of interest to you - foremost is smelting, a nice article which is really the answer to your question. Basically, most metals are found in nature as ores (another good article listing the common mineable ore forms of metals).  Ores are just bodies of rock containing metals.  Usually in ores the metals are trapped as oxides or sulfides, meaning they have been oxidized and are now salts.  In order to extract them, they must be reduced, meaning something must remove the oxygen or sulfur or whatever has oxidized it and take away the extra electrons so it is a neutral metal again.  This is accomplished with a reducing agent, which in ancient times would have been charcoal.


 * A miner would find rocks containing the ore, for instance hematite, the ore from which iron can be extracted, by the characteristics of the rocks, or by the characteristics of the places in which it is often found. He would probably break up the rocks into gravel or powder, then put it under a wood fire, probably in the bottom where there is little atmospheric oxygen.  The carbon in the charcoal, when heated in the fire, would reduce the hematite (Fe2O3) into iron metal (in the case of oxides like hematite the carbon would be oxidized and turn into carbon dioxide).  He would then probably wash the ashes and little bits of iron metal would be left behind.  Once he had enough metal, he could melt them into a bar, make a nice sword, and smite all the poor souls who were still using wooden spears.


 * If you were looking for more specifics about the actual mining of the ores, there is some information about this in the articles about the Bronze Age and the Iron Age. Hope this helps, and everyone else keep me honest - make sure that was accurate.    --Bmk 04:48, 8 July 2006 (UTC)


 * The Middle Ages (I am assuming you in Europe) just carried on from Roman mining(see Roman Deep-vein Mining by Lynne Cohen Duncan on the University of North Carolina website). "Finding" was by seeing the ore or metal above ground (and remained so until modern geological techniques changed things - when was that?). The technique itself was still opencast (surface excavation) and deep-vein mining (tunnels), as in Roman times, with minor improvements in ways of mechanically managing water and ore. From the University of Nevada site: Copper in the Middle Ages and Renaissance. Also Gold in the middle ages, by Rafal Swiecki. This page on Technology in the Middle Ages History of Technology, from the Department of Aviation and Technology at San Jose State University, gives information and good links. Interesting for me was the info that Saxon (German) miners were apparently "in demand all over Europe, leading to German terms being common in mining" (I'd like to know more about that too) and that the status of miners changed from that of serfs to freemen / artisans. The external links given have references to contemporary medieval writings on the subject, but these would be more difficult to come by. --Seejyb 13:26, 8 July 2006 (UTC)

Want to learn more about Ozone Generators
I searched for information both here and on the web without success. I am interested in building an ozone generator. I do not want to build the small units built by pot growers but instead, the larger units used for shock treatments of homes for odor control. Something in the 14,000 mg/hr range.

I know the internal workings but am having difficulty with creating the corona discharge. I would like to build a tube designed corona discharge instead of the plate type. I attempted to buy replacement tubes from ozone generator manufacturers without success.

My questions to you good people are as follows: Does anyone have plans for a high output ozone machine that includes how to build each part (Obviously the corona discharge tube)? Does anyone know where I can obtain such info?

I attempted to search the patent office for them (my favorite search location) but have not had any luck finding anything. The commercial ozone generator sales companies guard their secrets and fight with each other but none will tell you anything and it is quite frustrating.

My reason for all of this is I want to start a business with the ozone machines but have a lot more satisfaction making them than buying them (and it is usually cheaper). I would be just as happy finding a source for the corona discharge tubes that I could purchase.

When you are not sure what to do, ask people wiser than yourself. So, I'm asking.

Thanks

--Diabolic 04:21, 8 July 2006 (UTC)


 * This is very specialized and very dangerous (high voltage). You probably won't get much help here, sorry. --Zeizmic 15:11, 8 July 2006 (UTC)


 * bigclive looks like the kind of guy who could advise you. This page has his an email address. --Seejyb 20:00, 8 July 2006 (UTC)

Lightning rod
I live in an area where the occurance of lightning is frequent. Although my dwelling is surrounded by electrical poles and large oak trees and other houses about 1 out of 3 rain storms will produce a lightning bolt that hits the main 4 inch cast iron vent pipe coming out of the roof from the bathroom wet wall. The burst must jump to the water lines in the wall because the lines are immediately filled with calcium and rust build up on the inside of the pipe which clog the faucet filters and produce very brown to dark black water which must be flushed from the lines for up to 15 minutes. Would installation of lightning rods near the vent on the roof prevent this from happening or has lightning picked my house and my main vent as its eternal grounding buddy? ...IMHO (Talk) 10:15, 8 July 2006 (UTC)


 * Well that's exactly what lightning rods are for, so as long as it is well grounded and extends well above the top of the pipe, it should do the trick. Incidentally, as flying aircraft are not grounded, why are they sometimes struck by lightning? I would guess because they just happen to get in the way...--Shantavira 12:45, 8 July 2006 (UTC)
 * Alternatively, could you replace the iron pipe with plastic?--Shantavira 12:59, 8 July 2006 (UTC)


 * Only at unreasonable expense although both water and sewer have long since been replaced with plastic between the house and the street. ...IMHO (Talk) 15:00, 8 July 2006 (UTC)


 * A lightning rod would probably not prevent strikes, but would divert the strikes so most of the current does not flow through the water pipes. Another advantage would be that the ligntning conductors would be designed to make sure no fire starts; with the water and sewage pipes, it's just a matter of luck that nothing more serious than dirty water has happened. The lightning protection system should of course be installed by a licensed contractor. Gerry Ashton 19:43, 8 July 2006 (UTC)

Half life of common medications
Is there a list of in the body half life for various off-the-shelf medications such as aspirin? ...IMHO (Talk) 11:10, 8 July 2006 (UTC)

No easily accessible list, but if you google "generic name pharmacokinetics" (e.g. acetylsalicylic acid pharmacokinetics) and you will get links and refs (e.g. ). I am not sure what you will do with the data, as the primary use for half life data is for interpreting blood levels of a drug (for the drugs we monitor by blood level) drawn at a known time after dosing. alteripse 11:40, 8 July 2006 (UTC)


 * Actually I'm looking for parity data based on time from oral intake that can be adjusted for weight, medical condition etc. since such information might not only help consumers have a better feel for dosage, etc. but also might serve as a diagnostic tool in terms of observable half life deviation from normal, i.e., interval before return of pain or other symptoms, etc. ...IMHO (Talk) 14:57, 8 July 2006 (UTC)


 * From practical experience with the difficulties doctors and nurses have with using pharmacokinetic data, I have a pessimistic suspicion that you could put random numbers in your tables and outcomes would be indistinguishable. I think that's why there are no consumer tables. For example, are you interested in drug level half-life or biological effect half-life or average duration of effect or FDA-approved dosing interval instructions? After single doses, or steady states? Duration of effect does not bear the same mathematical relationship to either blood level or biological effect half-life for every drug. Finally, you picked one of the worst possible example drugs: duration of analgesic effects are notorious for being dependent on far more variables than drug half-life. You are proposing a thesis project for a Pharm. D. degree-- make sure you get credit for it. alteripse 19:46, 8 July 2006 (UTC)

Effect of radiation on water
Can electromagnetic radiation (photons from lasers), Gamma, Alpha, or Beta radiation separate molecules of water into their constituent parts of hydrogen and oxygen in a manner that does not render water or its constituents radioactive? ...IMHO (Talk) 15:27, 8 July 2006 (UTC)
 * Do we get to use a catalyst? --jpgordon&#8711;&#8710;&#8711;&#8710; 15:42, 8 July 2006 (UTC)


 * Not if it requires that I take time off from work. ...IMHO (Talk) 15:43, 8 July 2006 (UTC)


 * Sure, ionizing radiation (alpha, beta, and gamma) can ionize water. Not "photons from lasers", though, unless it's a gamma ray laser. It's a terribly inefficient method of separating water into hydrogen and oxygen, though. Most of the ion pairs just recombine immediately. —Keenan Pepper 16:10, 8 July 2006 (UTC)


 * So then its not like I could somehow use nuclear waste to generate hydrogen for fuel and oxygen to breath? ...IMHO (Talk) 17:27, 8 July 2006 (UTC)


 * You could possibly use the waste to generate heat (Hydrogen + Oxygen is exothermic), which could produce steam, drive a turbine, and then split some other water by electrolysis, but I doubt all but the highest level waste would produce more than a tiny bit of heat. smurrayinch e  ster( User ), ( Talk ) 17:37, 8 July 2006 (UTC)


 * Note that gamma radiation is a high energy form of EM radiation, not a separate phenomenon. --Bmk 18:15, 8 July 2006 (UTC)


 * Side point: "So then its not like I could somehow use nuclear waste to generate hydrogen for fuel and oxygen to breath?" With the water you split you will not be able to use H as fuel AND breath the O, because the O is needed to burn the H. One or the other. --GangofOne 22:12, 8 July 2006 (UTC)


 * Well, you could, in that excess oxygen exists in the atmosphere, so you can burn the hydrogen in air. That leaves the oxygen available for use in SCUBA tanks running trimix, for example. StuRat 22:55, 8 July 2006 (UTC)


 * That's not a side point, that was IMHO's point it seems. And Keenan already said it would be way too inefficient. Think about it. The energy could at most be that amount of energy in the radiation and if that were anything substantial it would be way too dangerous. Not that it isn't, but it takes just a little bit of energy do lethal damage to living tissue. DirkvdM 08:57, 9 July 2006 (UTC)

microbiology
how does a cell make a membrane protein, from dna to mature protein?


 * Please don't ask entire homework questions (I'm guessing this is a homework question, though i may be wrong). I can't answer the question for you, but you might find some information at membrane protein or by searching google. -Benbread 18:55, 8 July 2006 (UTC)


 * You probably want to read the article on Protein biosynthesis. - Mgm|(talk) 21:45, 8 July 2006 (UTC)


 * an incredibly broad question, imo too broad to be homework. you want transcription, translation, translocon, endoplasmic reticulum, golgi apparatus, secretion, cell membrane, integral membrane protein. a lot of work there, enjoy. Xcomradex 22:44, 10 July 2006 (UTC)

Chest hair
Why do I only have a single spot, about 5 cm by 5 cm, on my the left side of my chest that keeps growing chest hair? It's bugging the hell out of me. I want either a completely hairless chest or a chest that grows hair in a larger, symmetrical area. What can I do about this? J I P | Talk 19:07, 8 July 2006 (UTC)


 * It just happens that way at times. I suggest shaving it until it comes in more evenly, especially if you are a woman. :-) StuRat 22:50, 8 July 2006 (UTC)
 * lol, that's so mean Stu =D --mboverload @ 23:32, 8 July 2006 (UTC)


 * He is lucky Stu answered first. I would have diagnosed him with unilateral pectoral hypotrichosis (or hypertrichosis, depending on which side he wants to consider normal), recommended unilateral depilation (or unilateral minoxidil) and charged him $200. alteripse 04:39, 9 July 2006 (UTC)
 * Gee, no Wikipedian discount? Tito xd (?!?) 05:16, 9 July 2006 (UTC)
 * That is the discounted fee. alteripse 12:46, 9 July 2006 (UTC)
 * Some people have traces of a third nipple that shows up as a small patch of hair on the side of the chest. TheSPY 17:13, 9 July 2006 (UTC)
 * No, hair grows around nipples (i.e., periareolar), not on them. Accessory nipples are not the same as hair patches-- they are usually reddish bumps along the milk line. alteripse 17:45, 9 July 2006 (UTC)

hyperterminal
Hi, I'm interested in writing a program in Python/C++/VB 6.0 that people can connect to over the internet with Hyperterimal or another similar client. Wondering where to start...

I would like the program to accept commands from Hyperterminal, process them, and send back a result (eventually I hope to make a working, albeit very simple MUD)

Thanks, -Kyle
 * There are many ways. But why not start by experimenting with "telnet"? On the server machine, write some shell scripts or other programs that return stuff, then connect to that machine remotely and invoke those scripts. --GangofOne 22:19, 8 July 2006 (UTC)


 * yes, that might be a good starting point. Thanks,-Kyle


 * One thing to keep in mind is that, regarding the server, the simplest solution isn't the best. When supporting only a single client, a simple server can just accept a connection over a socket and wait for input from the client, then execute input when it arrives and send back the results of its processing. When multiple clients come into the picture, however, the server can't wait on a single client: you need to be a bit more clever and have it, e.g., cycle through each connected socket, buffering any input until it finds a newline character, then executing that particular client's command and continuing cycling. Likely you can find example code online to do this sort of thing. 128.197.81.223 23:21, 8 July 2006 (UTC)

Hatred between gulls and magpies
I've seen this happen a few times - gulls and magpies seem to have a mutual dislike of each other. Today I observed a magpie and a lesser black-backed gull stood on opposite sides of the roof, eying each other up aggressively. The magpie was chattering angrily, while the gull was giving it an icy stare and lowering its head to the ground as though to attack (as they do). Neither would back down and it ended up with both birds running headlong at each other and a session of squabbling, biting and flapping. The fight went on for a good minute or so.

This is not the first time I've seen this sort of thing happen. As well as individual fights, I've seen groups of magpies attacking groups of gulls, groups of gulls attacking groups of magpies, groups of magpies hassling lone gull fledgelings, groups of gulls hassling lone magpie fledgelings, both species chasing each other in flight, etc.

Anyone know why this occurs?

For the record (before anyone starts one of those 'who would win in a fight?' threads), the magpie came out on top. It seemed to have slightly faster reflexes and managed to evade most of the gull's pecks, whilst managing to inflict enough of its own to eventually cause the larger bird to lose its nerve. --Kurt Shaped Box 22:32, 8 July 2006 (UTC)


 * Kurt, I see you still have nothing but gulls on that diseased brain of yours...time to administer electroshock therapy...BZZZZZZT. There, is that any better ? StuRat 22:44, 8 July 2006 (UTC)


 * Hey! I mentioned magpies too! C'mon - it was too cool not to mention... ;) --Kurt Shaped Box 22:52, 8 July 2006 (UTC)


 * I carefully positioned the electrodes to preserve the magpie portion of your brain, at least until that becomes a fetish and requires a second round of electroshock therapy. :-) StuRat 22:59, 8 July 2006 (UTC)


 * Awwwww! Just answer the question willya? The suspense is killin' me... ;) --Kurt Shaped Box 23:24, 8 July 2006 (UTC)

Any warfare, either within a species or between species, is likely to be over competition for a scarce resource (assuming neither preys on the other). Perhaps they are in competition over food, nesting places, etc. ? StuRat 23:33, 8 July 2006 (UTC)


 * Thanks, dude. :) I've just been thinking about it now. Both species are known to eat the eggs of other birds from time to time, though it would take a *very* brave predator to attempt a raid on the nests of either of these species. I suppose that magpies do occasionally steal gull eggs and vice versa - which I suppose could go some way explain it. When both species come into contact, there is nearly always an instant agressive response, so perhaps they do perceive each other as a threat. --Kurt Shaped Box 23:43, 8 July 2006 (UTC)


 * Also, aren't magpies notorious thieves ? Perhaps they steal nesting material from the gulls. StuRat 23:48, 8 July 2006 (UTC)


 * On a couple of occasions, I've seen them trying sneak up and steal (i.e. pluck) feathers from sleeping gulls, much in the same way as they have been known to pull fur from cats and dogs to line their nests. This annoys the gulls, as I'm sure you can imgaine (I cannot personally understand why they take such risks with species more than capable of killing them). --Kurt Shaped Box 00:00, 9 July 2006 (UTC)


 * OK, we have more than enough reasons for gulls to hate magpies, I suggest the gulls attack and this causes the same response from the magpies. StuRat 00:21, 9 July 2006 (UTC)


 * I suppose magpies are called thieves by humans because they like shiny things, just like humans do (very much so, if you look at silver prices). If they would just 'steal' branches for their nests we wouldn't call them thieves because we don't give a Stu rat's arse about branches. DirkvdM 09:17, 9 July 2006 (UTC)


 * I call anything that takes possessions of another animal a thief. I suppose one could argue for theft from a plant, as well, but since dead, fallen branches are typically used for nests, that certainly isn't theft. In the case of magpies, stealing fur and feathers currently attached to cats and birds most definitely counts as theft, and I don't blame those animals at all for being rather upset over it, even ignoring the pain. StuRat 16:55, 9 July 2006 (UTC)


 * Can you be called a thief if you don't know you are one? Something like the difference between murder and manslaughter. The intention also counts. How can a magpie know that a ring belongs to someone? I don't mean that animals don't know the concept of possession (else they'd be perfect commies :) ) but do they even know that the house they find it in is someone's possession? It's just a (fancy) cave that some other bipedal creature also frequents. For inhabitants of a house, we use most parts of it very infrequently, compared to other animals' 'homes' (nests, from a magpie's perspective). DirkvdM 08:48, 10 July 2006 (UTC)


 * Don't you even admit they can be called thieves for stealing feathers currently attached to a gull ? StuRat 21:30, 11 July 2006 (UTC)


 * I've got a view of a fair bit of feathered wildlife from my window and noticed that coots are also incredibly aggressive. They attack anything that comes near them (except for swans - they're not that stupid). They even attack their own young. I suppose a lot of birds do that to tell them to go live on their own, but the coots are really aggressive, pecking their heads hard and chasing them for a long time to do so. Once some ducklings came close to a coot, which started an attack but was stopped by a very brave duck mother. I was impressed (and so was the coot). Don't mess with a mother! DirkvdM 09:17, 9 July 2006 (UTC)


 * There's a really horrific scene in David Attenborough's "Life of Birds" series in which parent coots systematically harass, attack and kill several of their own chicks. This apparently happens once they've decided which ones are the strongest and most likely to survive - the others are thus a drain on resources and expendable. I know that nature is 'red in tooth and claw (and beak)' but I was really distressed by it. --Kurt Shaped Box 11:08, 9 July 2006 (UTC)


 * Hey, I like magpies, so I'll comment on the gull question too. I wouln't anthropomorphize these birds to the point of describing them as harboring hatred or holding grudges. However, territoriality based on competition (both are scavengers, after all) is a probable reason for the behaviors. I see it with songbirds, too -- for example, starlings chasing robins. --Ginkgo100 talk · contribs 20:45, 9 July 2006 (UTC)


 * Further to the above, my freezer broke down yesterday and I ended up with a couple of loaves of soggy bread, which I threw out for the birds this afternoon. One of the local black-backed gulls was sat on the roof opposite, keeping an eye on the bread but showing no interest in eating it (as far as I know, gulls don't particularly like bread and will only eat it if they're hungry and there is no other food around). A couple of magpies flew down and started to eat, at which point the gull suddenly became *very* interested and started attacking the magpies. It swooped down, deliberately crashed into one of the birds and tried to bite its throat. The typical struggle, flapping, bickering and aerial chase followed, though this time gull and magpie were grappling with their beaks in mid-air, which was quite interesting to observe. You've gotta love gull logic - "This food is mine. The fact that I don't want or need it does not alter the fact that it is mine. Those that attempt to take what is mine are my enemies. I must attack my enemies". It seems almost human... ;) --Kurt Shaped Box 23:59, 9 July 2006 (UTC)
 * I have this really interesting image of a little shed on a tiny island completely covered in gull feces owned by a tiny shriveled old Britain that has fed the resident gull population for so long that they have permanently taken up residence in his chimney and are starting to get possesive about who get's to be the "master's pet". freshofftheufo  ΓΛĿЌ  05:20, 10 July 2006 (UTC)

I lived the first two decades of my life in a building that had birch trees on one side and a somewhat lower building on the other. We regularly had crows or magpies nesting in the trees and gulls nesting on the roof of the adjacent building. Over the years, I made a couple of observations that seemed to hold almost always: All in all, I got the distinct impression that, when nesting sites are not too crowded, both gulls and corvids tend to avoid nesting too close to others of their own species, and will go to considerable efforts to drive away any other species which they percieve as competitors. Of course, this has to be conditional behavior; gulls nesting in crowded island colonies certainly can't affort such luxury, if they want to nest at all. —Ilmari Karonen (talk) 22:08, 10 July 2006 (UTC)
 * 1) On the side with the trees, we'd have a pair of either crows or magpies, but not both. They'd compete over the same nest, which got rebuilt year after year, and one species or the other would win.  Often the losing couple would try to build a nest in a nearby tree, but they rarely succeeded in raising chicks; either they'd be chased away while trying to build a second nest too close to first one, or they'd choose a less suitable place for their nest and have it destroyed by wind, squirrels, humans and/or other birds.
 * 2) On top of the adjacent building, there'd be one gull nest, usually of herring gulls. Sometimes the smaller common gulls or black-headed gulls would try to build a nest at the other end of the roof; the herring gulls would drive them off or kill them.  I never saw more than one herring gull nest on the same roof, although there usually was another one on top of our building.
 * 3) The gulls did harrass the corvids, and vice versa. Usually the gulls seemed to have air superiority, but the crows and magpies had one major advantage; they were safe in the trees, where the gulls couldn't safely follow them.  So the gulls and the corvids would coexist, if grudgingly.

MUD with largest player base
google searches have failed me. I'm looking for a list of the current largest MUD's on the net.

If http://www.topmudsites.com/ is to be believed, then

http://en.wikipedia.org/wiki/Aardwolf_MUD

is one of the largest?

Thanks, -Kyle

Wattage
How many watts is 120V 60Hz AC at 0.45 amps? What is the formula to solve such problems? Thanks. - MSTCrow 23:57, 8 July 2006 (UTC)
 * see Power (physics) and Electric power --GangofOne 00:15, 9 July 2006 (UTC)
 * So it appears to be 54 watts, if I'm doing this correctly. - MSTCrow 18:07, 9 July 2006 (UTC)
 * Yes, assuming a purely resistive phase factor (which in fact you have to or else there isn't enough information in the question). Arbitrary username 22:06, 9 July 2006 (UTC)

memorize WAV (like "hi!") Watts = Amps * Volts. WAV. You have to have to have to memorize that. Hey there! wav.