I've been wondering about this for a while. Does anyone have a rough estimate of the probability of life on Gliese 581c? Thanks in advance! Gbgg8900:54, 11 June 2007 (UTC)[reply]
No one really has any idea, because we only have one data point in the universe for life, namely our planet; extraterrestrial life could potentially bear little resemblance to our own. That being said, that chance that Earth-like life (say, carbon-based with water as the solvent for chemical reactions) existing on Gliese 581 c is very, very small, because estimates for the temperature on the planet didn't account for its atmosphere (which is unknown). Very likely the planet looks more like Venus than Earth, making it far too hot for life. zafiroblue05 | Talk01:51, 11 June 2007 (UTC)[reply]
It's really impossible to know - we could perhaps say for sure that "life as we know it" (carbon/water) is impossible because of some temperature or radiation problem on the surface - but that's about the limit of what we could say - and even then we're on shakey ground.
What about underground where life might be shielded from radiation - or at the poles where it might be cool enough?
Are there perhaps strategies that extremophiles may have developed that we havn't thought of yet?
What about life as we don't know it? Life based around other chemistry is something that science fiction talks a lot about - but there is little doubt that the complex chemistry required strongly favors carbon/water life forms - but that doesn't necessarily make life based around exotic systems of chemistry impossible.
Life as we don't know it might be self-reproducing data with no chemical basis - something like patterns in sand dunes that maintain their shape, split in two, consume other patterns in order to retain their shape? Something weird like that might be classifiable as life yet have no specific material existance.
What about intelligent life that developed elsewhere and travelled to that world where they live in highly protected artificial environments?
I came upon this question in a search and realized this would help. Some Albedo/Emissivity combinations (extremes) are unrealistic.
=((((R^2)*σ*(Te^4)*(1-A))/(4*ε*(d±(d*e))^2))^0.25)-273.15 24.78.167.139 (talk) 17:34, 30 May 2010 (UTC)[reply]
Glass
Can some one tell me the process for making glass? I also want to know the historical origin of glass. —The preceding unsigned comment was added by 196.200.102.42 (talk • contribs).
You might start with the articles on Glass and Glassblowing (which contains a brief description of the process of making molten glass, and a description of one method of shaping it). You can find even more articles by using the search box on the left column of your window. Come back if you have more questions. --TeaDrinker07:14, 11 June 2007 (UTC)[reply]
I'm about to embark on a series of rewrites involving animal anatomy & would love to have a partner in crime. This would involve polishing any articles that I've rewritten or expanded to make sure I haven't made any mistakes & to add anything I've missed. The said person must have fairly good knowledge on anatomy in animals in order to make up for my shocking knowledge of the subject ;). Anyway, more than one person would be great, and I'm going to start in the next week or so. Work doesn't need to be finished straight away, but a collaborative effort needs to be kept up. If you're up for it, leave me a message on my talk page or here & I'll send you the article links when I'm done with them. alas, no rewards available this time round. Cheers, :) Spawn Man09:46, 11 June 2007 (UTC)[reply]
What is a shaft passer?
I had read somewhere that it allows a shaft of a gear or a wheel to pass through the spokes of another wheel. Wikipedia doesn't seem to have an article on this. No joy on Google either -- WikiCheng | Talk11:57, 11 June 2007 (UTC)[reply]
It was invented by the Germans during the war to keep the British minesweepers from catching the cables that held the German mines floating under the sea at a certain depth. With these "shaft passers," the German cables could allow the British cables to pass through as if they were going through a revolving door.
Response 2:
It is actually a Russian WW1 invention as far as I'm aware. Think of it as two cog wheels built into the mine's mooring rope. The two wheels are connected by metal spokes that rotate with the wheels and alternatingly engage and disengage on locking mechanisms fitted on to the opposing wheel's axle, so that one spoke at least (in fact a pair - to the left and right of the wheel), always keeps the connection between the mooring ropes. Now, when the sweep wire rides up on the mooring rope, it encounters the two cog wheels. The cogs transport the wire over the wheels. As the spokes on the forward side disengage, the ones that come behind the wire engage and thus maintain the connection. That's it. I'll chase a drawing if you wish.
That's where I heard about a "shaft passer", too—and it's the only place. I've tried just about every clever Google search I can think of since then, and I'm coming to the conclusion that our search for a 'shaft passer' may well demonstrate that Feynman was either the victim or perpetrator of yet another clever practical joke.
Just a couple weeks ago I saw a device on a man-safety line that allowed a carabiner to pass by the connection points that anchored the line to the fixed stanchions supporting the line. The application was at a canal lock, the line was attached to a wall that ran alongside the lock horizontally for a hundred feet or so, and the lock workers wore harnesses that had a lead which they clipped to one of these devices on safety line, to prevent them falling into the lock if they got too close to the edge. I suspect someone more familiar with climbing gear, or industrial safety gear has seen and/or used these things... I tried to figure out how it worked (I could see it, but not get closer than a couple of feet). It appeared to be very similar to the device described above with two cogs, and spokes. As the lock worker walked along the wall, the device would come across a place where the line was anchored to the wall with an eye bolt, and the device would travel over the eye bolt without disengaging from the safety line. Would that device be considered a "shaft passer" ? Is there another commonly-used term for it?
I suppose it is the same mechanism, used for a different purpose. It looks like there was an article (or a yet-to-be-created article) in Wikipedia on shaft passer sometime back. There is a mention of protecting the page here. Thanks to all of you for trying to enlighten me but I still haven't got beyond having a hazy idea of what a shaft passer is. But I am convinced that there is something. Please have a look at [2] too. I have a feeling that it is also referred to as an 'avoider'. -- WikiCheng | Talk04:59, 12 June 2007 (UTC)[reply]
First, WikiCheng, sorry for telling you what you already knew when it came to SYJMF.
Second, 71.112.132.210, that mention of a "passer" for carabiners and a fixed safety line is interesting. It's an easier problem, though, as what we have there is a device that's normally attached to a line. By attaching it at two adjacent points, and allowing one attachment at a time to be temporarily disconnected, an obstruction can be easily passed. (Furthermore, in the case of the safety equipment, there's not normally much force on it, as long as the worker is not in the process of falling.) But what we're talking about wrt a "shaft passer" is a device that can allow two normally-disconnected shafts or lines to pass each other without interference, and moreover while they're both potentially under significant tension (or compression).
Finally, if anyone's still not visualizing what the hypothetical shaft passer would do, take a look at the picture at the right, and imagine that one of the shafts supporting one of the auxiliary gears were routed through one of the spoke holes of the large gear in the middle. Obviously the mechanism wouldn't work very well, because as the large gear rotated, it would hit the intruding shaft, either breaking something or jamming the machinery. But if there were some magical mechanism in the middle of each of the (in this case four) spokes which could open, one at a time, to allow the shaft to pass as the large gear turned...
You might be able to do it with strong magnets. Basically take two bar magnets and stick them on their sides to the ends of the shaft you want "passed through" the gear. As one shaft turns the other will turn so that the magnets are parallel with each other and the opposite poles across from each other. Of course the turning shaft would have to have relatively little resistance on either side compared to the strength of the magnets for this to work. Sifakatalk22:35, 12 June 2007 (UTC)[reply]
Thanks a lot Ilmari! Thank you very much ! As you mentioned, it feels almost obvious. If I draw this (copy it from the picture you provided), is it good enough (legal) to be put in Wikipedia? -- WikiCheng | Talk05:40, 13 June 2007 (UTC)[reply]
Redrawing a copy of the illustration would be a copyright violation. However, drawing an original picture of the mechanism — from a different angle for example — based on the information given in the illustration should be OK. —Ilmari Karonen (talk) 19:56, 13 June 2007 (UTC)[reply]
IMPORTANT!. Shaft passers exist.. Not a wild goose chase. Simply place cogs (free to rotate) on the passed shaft - then use a cog on certain shaft and cogs on inner rim of outer wheel - this works - see original question "allows a shaft of a gear or a wheel to pass through the spokes of another wheel" -
Hypothetical Runaway Greenhouse effect
I was reading Greenhouse effect and also Venus and got to thinking. If life had not evolved (or created, depending on viewpoint), would the greenhouse effect escalate to the point of venus? This is assuming that the sun is stable, and has an infite supply of hydrogen to continue on it's Main sequence indefinately, no intervention from comets, ateroids, alien life, supernovae, etc. My assumption is that the atmosphere would eventually look like Venus based on so far what I've read. With constant heat from the sun, the earth radiates pretty much as much heat as it recieves from the sun, but volcanism should increase the amount of CO2 in the atmosphere, which causes the greenhouse effect. That makes the earth retain more energy then it is letting off. But is there enough CO2 escaping from the atmosphere to balance this effect?
On another note, it doesn't look like anything severe has happened to Mars yet, unless we can say the atmosphere is 95% Carbon Dioxide due to the greenhouse effect. --GTPoompt(talk)14:14, 11 June 2007 (UTC)[reply]
Don't forget the difference the distance from the Sun makes. Mars may very well need a "runaway greenhouse effect" just to keep the temp livable (for humans) at that distance from the Sun. Smaller planets, like Mars, also cool more quickly than larger planets, losing their geothermal (or equivalent) sources of heat. StuRat15:31, 11 June 2007 (UTC)[reply]
What happens (without life of any kind, including that which build machines to burn fossil fuels) is that the level of CO2 in the Earth's atmosphere is in equilibrium: Just as volcanoes transfer CO2 from the Earth to the atmosphere, so too does CO2 from the atmosphere re-combine with oxide and hydroxide minerals, converting them to carbonates and bicarbonates (a "locked up" form of CO2) and thus transferring the CO2 back from the atmosphere to the earth. This is a cyclical process, and the Earth is just far enough from the sun that this is a stable equilibrium. -User: Nightvid
Just a guess. Slow rotation and no orbital eccentricity probably contributed to the demise of liquid water. I think retaining the vast oceans on earth and the mechanism that does it is what keeps the earth in check. Keep in mind that water was the principle greenhouse gas on both planets, not CO2. On venus, the water evaporated and is gone and CO2 cocentrations went nuts (95% on venus versus 0.04% on Earth). A runaway process on earth would be oceans evaporating and adding more water the to atmosphere. CO2 may cause minor fluctuations, but to see venetian style global warming would require a water vapor driven process. This seems to be independant of life on the planet as the earth has been both warmer and colder as well as volcanic but never runaway. --Tbeatty09:54, 14 June 2007 (UTC)[reply]
A website for getting introduced to quantum mechanics
Regarding the above subject I humbly request the desk volunteers to suggest me a good website that would give somewhat elaborate introduction to quantum mechanics.
Many webpages as far as I searched the introduced quantum mechanics with birds eye view about wave function. How to use the wave function to calculate a particles position at point B if it started at point A having x momentum when such calculations involves wavefunctions having many imaginary quantities? Webpages that start dealing with wavefunction didnt deal with any numerical example as one above. And the topic gets advanced as one reads through.
Thanks.
signed 121.247.214.22615:15, 11 June 2007 (UTC)[reply]
I think they are valid content forks. I agree that the content also belongs in Wikiversity or Wikibooks, but it accords with all the WP policies, and is not a duplicate to the more technical articles. It's comparable to the situation in most United States colleges where there are separate courses for majors and non majors. YechielMan15:38, 11 June 2007 (UTC)[reply]
yes... well.... that's a dreadful precedent. If we begin to write articles for majors and non-majors, and then for highschoolers and preschoolers, they will be a nightmare to maintain. I appreciate the value of these articles, but I really think they belong on a sister-project. That's not in any way a devaluation, it's precisely why these projects were created, and hosting the articles here instead of there amounts to "brain-drain" to those projects. dab(𒁳)16:34, 11 June 2007 (UTC)[reply]
The original question asked how to calculate the particle trajectory, given its starting conditions (position and momentum). That is classical mechanics, by definition. Quantum mechanics is a wholly different conceptual framework, and does not have descriptions for things like "trajectories." There is only the wave function. Given the starting conditions (i.e. initial wave-function), the end-result (resulting wave-function) can be calculated. Position and momentum are a measurement of the wave function, instead of fundamental properties (as they are in classical mechanics). Nimur22:06, 11 June 2007 (UTC)[reply]
this is not strictly true. The notion of trajectory is very much part of quantum mechanics, in the path integral formulation. There is "just the wave function", sure enough, but the wave function expresses the probabilities for certain trajectories. dab(𒁳)11:30, 12 June 2007 (UTC)[reply]
I'd recommend doing a few searches for "six easy pieces", which was a lectures series at Cal back a couple decades that is still a great place to start learning about quantum physics. -Mask?02:34, 12 June 2007 (UTC)[reply]
Looks like it, although those are more recent. I had them on cassette that had a copyright date of 1983. -Mask?11:38, 12 June 2007 (UTC)[reply]
menstrual cycle
Apparently restricting sexual intercourse to the days marked 'infertile' results in a pregnancy rate of 5% per year, for women who always have menstrual cycles between 26 and 32 days in length.
on an average 28 day cycle, what are the most infertile days of the cycle?
I'm not sure what you're referring to but the table lists the typical failure rate for the rhythm method as 25% in the first year. The easiest way to think of this is that 1/5 couples using this method will get pregnant in the first year. The article explains some issues related to the failure rate in more detail Nil Einne18:52, 11 June 2007 (UTC)[reply]
Sudies show that if one uses the Standard Days Method correctly (as that image demonstrates) there is a 4.75% pregnancy rate, however, since people who chose this method rarely do it correctly, the typical rate is 11.96%. Rockpocket21:13, 11 June 2007 (UTC)[reply]
We found a fledgling at work today; unable to fly and at severe risk of a passing cat, it was a really sad sight. But it was completely fearless - it stood in a doorway and let people walk "overhead" - which meant I could sit a few feet away and get very clear pictures. Here's five. So, are we looking at a crow, a rook, or a jackdaw (my current guess) - or something else entirely? It's the old problem of juvenile plumage, and not wanting to read too much into colouring details, that measn I can't be sure... It was certainly pretty large, about the same size as an adult blackbird, so it must have been of a fair age for a fledgling. Shimgray | talk | 21:02, 11 June 2007 (UTC)[reply]
I'd agree, it definitely looks like a jackdaw. Identifying features: it's a corvid because of the dark bulge at the upper base of the beak and the appearance of the feet; its bill is too pointed and narrow to be a crow or a rook; it has the grey (rather than black) head, breast and nape plumage of a jackdaw and it has a jackdaw's pale whitish-grey eye. QED :-) --YFB¿22:10, 11 June 2007 (UTC)[reply]
Hello. Ground wires discharge objects and carries the charge to the ground. Can this charge in the ground cause lightning? Thanks. --Mayfare22:31, 11 June 2007 (UTC)[reply]
Dont think so- though it depends on how you define ground. Is a standing tree or a building ground? Lightning can certainly jump from a tree to you, thence to (real) ground. Since the potential difference is originally created between the cloud and the earth, once the charge has passed to ground there wont be any lightning produced from the ground because the charge cannot appreciably raise the potential of the ground.
This is not to say that you are safe: currents in the ground can produce lethal potential differences in the space of one stride. I believe it is quite a common occurence for cattle to be killed this way since they have a longer wheelbase than humans. If out in lightning waether, its better to take small steps (and keep low).
It is unlikely that any household utility electric circuit can supply enough charge or current to induce lightning; numerous safety faults and circuit breakers would cut off the power before a large charge could accumulate in a small amount of time. However, charge on the ground can accumulate as part of normal atmospheric lightning. See Lightning#Types_of_lightning for a discussion of ground-to-cloud, cloud-to-ground, and other strikes. Nimur18:07, 12 June 2007 (UTC)[reply]
Ah, another one of those things where we have to be careful about what "cause" means. If your lightning rod is the highest object around, then most likely the lightning will strike (either originating from or going to) that rod instead of striking something else. So it does cause strikes in a sense, the probabilities of where lightning strikes has been changed and hopefully the distribution is more localized (I wouldn't want to be near one in a thunderstorm!). But will it cause more strikes in the vicinity, given a big enough, but not absurdly big, vicinity? (maybe mile wide?) I would guess not. Root4(one) 04:40, 13 June 2007 (UTC)[reply]
Lightning rods are not supposed to "attract" strikes, they are supposed to prevent them by dissipating charge slowly (preventing a strike at all). It is a common misconception that they are supposed to be the "designated target" for strikes. Nimur20:46, 13 June 2007 (UTC)[reply]
This is somewhat disputed, and as far as I know there's actually no reliable evidence that lightning rods of any design would significantly prevent (as opposed to safely channeling) lightning strikes. Part of the difficulty is that, due to the unpredictability of natural lightning, and the infeasibility of creating artificial lightning strikes of comparable scale and energy, conducting reliable statistical studies of the effects of lightning rods under natural conditions is quite hard. Lightning rod#Evaluations and analysis may be useful reading, although, as is common with Wikipedia articles on controversial topics, it's also incredibly tediously written. —Ilmari Karonen (talk) 04:05, 14 June 2007 (UTC)[reply]
June 12
car engine question
At speed, if I was to slam on the accelerator, the engine RPMs increases immediately but it takes several seconds of high RPM for the vehicle to finish accelerating to its new speed. My question is, what mechanical component is between the engine and the drive shaft to allow the drive shaft to actually be accelerated instead of a violent and instantaneous change to the new engine rpm, and how does it work? --frotht00:25, 12 June 2007 (UTC)[reply]
Er, that sounds like you have things the wrong way around. You either have an automatic (in which case when you slam on the revs, the RPM increases because the gearbox downshifts to a lower gear; then the engine RPM goes up dramatically because the drive shaft is rotating at more or less the same speed as before the shift, but now the engine has to run faster "to keep up with it") or your clutch is slipping really, really badly (i.e. the engine responds to the throttle by increasing RPM [although this isn't instant] and the clutch doesn't have sufficient friction to accelerate the drive shaft at the same rate) - this would be a bad thing. Since you're in the US where hardly anyone knows how to drive a proper car ;-) it's probably the former. --YFB¿00:30, 12 June 2007 (UTC)[reply]
Well, sort of, but the question would make sense if it was an automatic. If you stand on the throttle, the gearbox will almost-instantly downshift and there will then be a near-instantaneous jump in revs. The several seconds Froth mentions is the car accelerating (with the revs increasing further) after the downshift. Or, as I said, he could have the world's most knackered clutch, but I think he'd be able to smell it if one plate was taking "several seconds" to catch up with the other :-/ --YFB¿02:45, 12 June 2007 (UTC)[reply]
My point is that the speedometer is clearly not moving in parallel with the -uh- RPM-o-meter. Obviously the two won't always read the same since there are gears in between, but even with gears, if you're accelerating how can the RPMs hold steady while the speed increases? Does the clutch keep slipping until you're at the right speed? And you're right, I only know how to use an automatic transmission, I hate cars and can barely put up with automatic, but the car is defying me with this stupid question :) --frotht14:08, 12 June 2007 (UTC)[reply]
The torque converter does allow some "slip", but most of what you're seeing is explainable just by gearing. The other "slack" factor you may see is that your gauges aren't instantaneous either. Generally they shouldn't be far behind, but you never know. Friday(talk)14:53, 12 June 2007 (UTC)[reply]
To first order, you shouldn't see an acceleration without an increase in revs - if the car is driving at constant speed then the revs will be constant, then when you increase the revs the increase in the speed of the wheels is the change in rpm divided by the gear ratio (approximately - not including assorted other transmission components, overdrive, etc.). So if you keep the revs constant, the only way to increase speed is to change to a higher gear, which will inevitably involve a change in revs anyway due to the engine being unloaded while the gears shift. You'd have a better idea what was going on if you drove a manual, since you have to match the revs yourself on downshifts to make them smooth. I hate automatics. There's nothing to do with your left leg and (particularly in the States where you don't have any bends either) it's too easy to fall asleep at the wheel through boredom. Not to mention the fact that the transmission steals a significant portion of your engine power just to save you using one arm and one leg every now and again. Bleh. --YFB¿22:46, 12 June 2007 (UTC)[reply]
With an automatic gearbox you might see a change in speed with only a small jiggle in RPM if it happens to shift while you're accellerating but generally, while you are in just one gear, the RPM and Speed are directly coupled by the gear ratio. One big difference would be with a Continuously variable transmission, it's very possible for the RPM to not change at all over a wide range of speeds. I had a MINI Cooper CVT as a loaner when my car was in for service and it's very strange to drive - as you put your foot down, the RPM's don't change at all until you get up to maybe 60 mph! (Unless you really stamp on the pedal) It's weird, you expect to hear the engine sound change - but it just doesn't. SteveBaker20:31, 13 June 2007 (UTC)[reply]
It promotes the production of kidney yin and prolonged use is beneficial for sexual weakness. Even though its greatest value is in its "love tonic" attributes, wild asparagus root is often used in tonics designed to overcome impotence or rigidity on the physical level.
So, If you believe your "kidney yin" is the cause of your "sexual weakness" then an asparagus root "love tonic" may be the treatment for you. However, TCM also advocates the consumption of animal testicles to boost sperm count, so you might want to try those first. Rockpocket02:04, 12 June 2007 (UTC)[reply]
First of all, you should ask your doctor this question, not a team of pseudo-anonymous volunteers. 1. That being said, the NSAIDS in a gel or liquid suspension might not work for any number of reasons. What active ingredient did you have in mind, if not aspirin? Ibuprofen? 2. I would doubt that most NSAIDs need to be metabolized to become active. In fact, most are hepatoxic. As the Non-steroidal anti-inflammatory drug article states: "Most NSAIDs are metabolised in the liver by oxidation and conjugation to inactive metabolites which are typically excreted in the urine, although some drugs are partially excreted in bile." --Rajah02:54, 12 June 2007 (UTC)[reply]
I don't understand what you said. I know this doesn't work, or else there would be products out there. I was referring to ibuprofen or aleve. Anyways, a doctor a) might not even know this b) I don't need to know c) I don't have rhinitis d) it would cost me 160$ to find out if the doctor did know. Thanks, though.
Careful...a possible, workable thing might not exist on the market solely because no company at this time finds it in its best business-interests to do so. The NSAID page teaches that the drugs are generally absorbed well via GI. Maybe the drug has poor absorption on mucosal membranes? The ibuprofen article suggests that half of the drug needs to be metabolized into a more active form. DMacks05:19, 12 June 2007 (UTC)[reply]
Don't NSAIDS have other effects on mucus membranes than just inflammation suppression? I was under the impression that the upset-stomach side effect of aspirin was due to less mucus, so maybe it would dry the sinuses too much. I think some of the reason is that steroids work pretty well in this application, and work at low enough doses that there isn't much sytemic effect.--Joel18:39, 12 June 2007 (UTC)[reply]
Insect cacoomb? cucomb? ARRRG!!
THIS WORD IS PROPELLING ME PRECARIOUSLY CLOSE TO INSANITY.
Insects can build house-like structres made from various materials; catepillars turn into butterflies inside of this structure.
The problem is spelling it.
cacoomb?
cacoombe?
cucoomb?
cucumb?
kacumb?
I do know it is NOT spelled: "coxcomb."
This word is either: A) some plant, or B) "a conceited, foolish dandy; pretentious fop."
Ahhh, that's it. Thank you kindly. As for the previous question, it's a process called verbal fronting. If the link isn't red, you can take a look. 'b' is easier to pronounce than 'n' (at least to USA Southerners); therefore most of us pronounce "cacoon" as "cacoombe." It is extremely fustrating at times (esp. when utilizing a dictionary). --67.177.170.9606:02, 12 June 2007 (UTC)[reply]
Do you really pronounce the b? How about in lamb? If in fact you mean the /n/ becomes /m/, I'm still surprised (though less so), because I'm told that in Spanish final m (e.g. in Latin words) is pronounced /n/, and I believe Spanish is not the only language with that habit. —Tamfang06:21, 12 June 2007 (UTC)[reply]
Yes, believe it or not, a majority of USA Deep Southerners pronouce lamb as "lahmmbe" (with a hard labial 'b') and cacoon as "cah-COOM-bh" (with a soft labial b). 'ń' (nat) and 'n' (skinny) are very hard sounds for us to make...haha. If I knew my IPA I would use it, but it's been a while. --67.177.170.9606:28, 12 June 2007 (UTC)[reply]
My car needed some brake repair, and the clerk writing me up looked at the tires and remarked, "Your tires are filled with nitrogen; you need to either use only nitrogen to pump them up, or have the nitrogen removed and fill them with air." What?! How can an intermediate blend of nitrogen be worse for my tires than either 4/5 (common air) or 5/5? —Tamfang06:25, 12 June 2007 (UTC)[reply]
The clerk is mistaken. Mixing compressed air in with the nitrogen will do no harm, but it will dilute somewhat the putative advantages of the nitrogen-only fill. You've either got a poorly-trained clerk, or you've got a clerk who thinks that you're gullible. ("It's not safe for you to mix that dirty, free air into your nitrogen-filled tires. Don't worry though, we'd be glad to top off your nitrogen for twenty bucks.")
Note that benefits of nitrogen for someone who drives under reasonable conditions are probably negligible: [4]. You can get the same improvement in mileage just by regularly checking that your tires are properly inflated. TenOfAllTrades(talk) 08:57, 12 June 2007 (UTC)[reply]
It's always important to maintain proper tire pressure. That preserves the handling characteristics of the car and helps prevent blowouts and other tire failures. All the nitrogen does is reduce the effect of temperature on tire pressure, and cars already have plenty of safety margins there anyway. — Lomn13:34, 12 June 2007 (UTC)[reply]
Yes, of course it's important, I just meant that with nitrogen, you might not have to check it as often to make sure the pressure is correct. I see how it could be misunderstood, though. :-) Also, everyone, remember that too low pressure means worse fuel economy, which will cost you more and, more importantly, harm the planet through more emissions. —Bromskloss14:56, 12 June 2007 (UTC)[reply]
More like less importantly since I have far more interest in my saving money than my personal, negligible impact on the environment --frotht04:33, 13 June 2007 (UTC)[reply]
The business of filling car tyres with nitrogen is a bit of a scam - you certainly have to continue to check tyre pressure. There are arguments that the air seeps out through the rubber more slowly with Nitrogen - but you still have to check them just as often because you still don't want to drive for weeks on a soft tyre until you get around to checking it again. Air leaks out for all sorts of other reasons - none of which are helped by using nitrogen. Find another tyre store - this one is clearly staffed with idiots. SteveBaker20:25, 13 June 2007 (UTC)[reply]
Here I assumed that the purpose was to reduce oxidation of the rubber (from within, obviously, we can't do anything about the outside but helping where you can is better than nothing). —Tamfang16:12, 14 June 2007 (UTC)[reply]
lens
if lens is halh covered ,what happens to image
Even if you cover up one part of the lens, there are other paths for the light to reach the image.
Ah, good question. I think the answer is that the image will get darker, not partially obscured. As you can see in the illustration here, the light emanating from an object can hit any part of the lens and end up on the correct spot on the image anyway. Therfore, if you cover one part of the lens, you will block some of the light, but are still lightrays from the object slipping through elsewhere. That said, some parts will probably be darker than others because a larger part of the lightrays from an object hit the part of the lens that is closest to the object and also because what I said is only true (I think) if you approximate the lens to lie in a single plane (not having anyt thickness). —Bromskloss07:59, 12 June 2007 (UTC)[reply]
(ec) Mostly, not a lot happens except that the image is only half as bright, or more technically, has only half the irradiance. Think about what happens when you half close your eyes. However, there can also be changes in the quality and sharpness of the image, depending on the lens or lens system, due to the suppression or enhancement of aberrations. Also, if the original image is somewhat out of focus, the image with the lens half covered may appear to be sharper, because of the effective reduction in f-number. But usually, you will still see all of the image. The ray diagrams under lens (or helpfully supplied here) may help to explain this. --Prophys08:07, 12 June 2007 (UTC)[reply]
On second thoughts, half-closing your eyes is not a good example, because in fact your field of view does become more restricted when you do that. This is an example of vignetting, which happens when you reduce the area of the lens with a screen or aperture that is not close to the lens, but some distance from it. Then you get partial dimming or even cutting off of the edges of the image. If the aperture is right next to the lens, (technically, at one of its principal planes), then the area of the image is not affected by the area of the aperture. As the aperture is moved further away from the lens, the effect on the area of the image becomes more severe. If the aperture is in the plane of the image, then the area of the image is obviously the same as the area of the aperture. --Prophys12:51, 12 June 2007 (UTC)[reply]
If the covering is some distance in front of the lens, there may be darkening of half of the image more than the other half. For this to work as expected, and cause overall darkening, I would expect it would have to be immediately in front of or behind the lens. To be sure that the only effect is overall darkening of the image, the ideal place for the covering to be is between the elements of the lens, at the nodal point, where the diaphragm, iris, or aperture is in a camera. Waterhouse stops were provided with early cameras. They were metal strips with different size holes in them which could be inserted in the lens. The goal of "stopping down" the lens is not so much to reduce the light going through the lens (the slow film of that era needed lots of light to make a good negative]] , but to restrict the path of the light to the center of the lens, where aberrations were least, and to improve the depth of field. One reason human vision is better in bright light is thet the iris of the human eye similarly "stops down" to keep the light path to the sharper central portion of the visual pathway. Edison13:12, 12 June 2007 (UTC)[reply]
If today's temperature is Zero degrees centigrade (0°C), the experts predict that it will be twice as cold tomorrow, how cold will it be in degrees centigrade?41.222.12.9111:38, 12 June 2007 (UTC)[reply]
that question is impossible to answer outside of context. Scientifically, there is no such thing as 'cold', just the absence of heat. You can take away or add heat to a substance, you can't add 'cold' outside of finding a way to remove the heat. -Mask?11:48, 12 June 2007 (UTC)[reply]
This question could be tackled if you adopt a "relative" stance. Relative to yesterday, when the temperature was (say) 5°C, the temperature has dropped by 5 degrees. So, if tomorrow is going to be "twice as cold", you could argue tomorrow's temperature will be -5 or -10 depending on how you define "twice". So... what was the temperature yesterday? Incidentally, if the problem is supposed to be about difficulties of multiplying by zero (which it isn't currently... it's about lack of information) you can always avoid the issue by working in Fahrenheit or Kelvin or whatever other scale you fancy (take a look here). --Dweller12:06, 12 June 2007 (UTC)[reply]
This sounds kind of like a homework question. If you assume twice as cold is the same as half the temperature, 0°C = 273.15K / 2 = 136.575°K - 273.15°K = -136.575°C. See Kelvin as noted above for more info.--GTPoompt(talk)12:13, 12 June 2007 (UTC)[reply]
The "experts" don't predict that it will be "twice as cold" tomorrow. They predict a specific temperature range; it's some wooly-headed reporter or other commentator who comes up with a claim like "twice as cold", which, as we've seen here, is fairly meaningless. (Me, I'd imagine that "twice as cold" means that (comfortable temperature - tomorrow's temperature) = 2 × (comfortable temperature - today's temperature), but we still get to argue over what "comfortable temperature" is.) —Steve Summit (talk) 13:01, 12 June 2007 (UTC)[reply]
Since dissolved salt in water doesn't stay salt, but splits up into the ions (Na+, Cl-), how does gargling with saltwater (which doesn't contain salt) actually kill bacteria in the throat? The common explanation is that salt causes the bacteria to barf up all their water, but that doesn't make sense if there's no salt in saltwater. — BRIAN0918 • 2007-06-12 12:01Z
Claiming that "salt water doesn't contain salt" is a typical act of pedantry. For all intents and purposes, salt water does contain salt, as (a) its name, (b) its taste, (c) the residue left after evaporation, and most importantly here (d) its effect across osmotic membranes and salinity gradients all attest. —Steve Summit (talk) 12:39, 12 June 2007 (UTC)[reply]
You haven't really given an answer. Is it that you have to add more salt than can be dissolved in the water? — BRIAN0918 • 2007-06-12 12:44Z
He was stating that your assumption that salt crystals are required to kill bacteria is a false one. A salt crystal is a stable molecule. It won't do anything. When dissolved (turned into active floating ions), the salt will do its job. --Kainaw(talk)12:52, 12 June 2007 (UTC)[reply]
(ec) I'm not sure why gargling with salt water works, either (though I have experienced that it does). But your explanation that it "causes the bacteria to barf up all their water" sounds perfectly plausible to me.
If you add more salt than can be dissolved in the water, the undissolved salt sits at the bottom as granules, and I wouldn't say that the water "contains" it. It's the dissolved salt, of course, that gives salt water its properties (bactericidal and otherwise). —Steve Summit (talk) 12:53, 12 June 2007 (UTC)[reply]
I'm getting the feeling you didn't really know the answer and are just restating other people's answers or using circular reasoning (as in your original post). That's fine, I can wait for someone who actually knows. — BRIAN0918 • 2007-06-12 13:11Z
I'm sorry, when you said "The common explanation is that salt causes the bacteria to barf up all their water, but that doesn't make sense if there's no salt in saltwater", I though you meant, "I can understand that salt would make the bacteria barf up all their water, but that doesn't make sense because there's no salt in saltwater." —Steve Summit (talk) 13:21, 12 June 2007 (UTC)[reply]
The trick is osmosis, which I think is what Ummit was trying to get at there, somewhere. The cell wall of a bacterium is a semi-permeable membrane, meaning it lets some things (like water) through and others (like sodium and chloride ions) out. When you gargle salt water, water rushes through the membrane in an attempt to equalise the salt concentrations - but, since the salt water contains a lot of salt, and the bacteria contain just a little water, what happens is that, in a sense, the bacteria "barf up all their water". Confusing Manifestation13:02, 12 June 2007 (UTC)[reply]
I'm confused. Why does the water rush out of the bacteria if the water inside the bacteria has less salt. I guess the confusion is what you mean by "equalize the salt concentrations". — BRIAN0918 • 2007-06-12 13:10Z
It's a fundamental principle (which I can't give an explanation for) that concentrations of dissolved substances want to equalize. If you have a higher concentration of solute in region A than in region B, you can equalize them either by adding solvent to region A (perhaps by moving it from region B), or by adding solute (e.g. salt) to region B (perhaps by moving it from region A). But if the regions are separated by a semipermeable membrane, that can pass solvent but not solute, then only the first option is available. —Steve Summit (talk) 13:21, 12 June 2007 (UTC)[reply]
Yeah, I just figured that out myself. I'm sure I learned it in one of my chem courses, but I obviously didn't retain that knowledge. I did, however, retain the loans. — BRIAN0918 • 2007-06-12 13:23Z
There is no evidence that gargling with salt water kills bacteria. Period. This is folk medicine (I was taught to do it by my mother also). From the standpoint of scientific medical practice it is a harmless "comfort measure", but do not imagine that it is accelerating your recovery from a bacterial infection-- most sore throats are viral. alteripse13:27, 12 June 2007 (UTC)[reply]
So where does the comfort come from. It does make you feel better temporarily. Why? Tufts says that it actually "washes away the layer of mucus on the throat containing bacteria". Why salt-water specifically? Would sugar water also have the same "washing away" effect? — BRIAN0918 • 2007-06-12 13:29Z
However, in answer to the "how does it soothe" question, I don't know. Some of the possible variables: (1) whether you have been told it is effective or ineffective, (2) warm, neutral or cold temp, (3) tonicity of the the salt (hypo-, hyper-, or normal), (4) solute in the water vs plain water, (5) salt, or sugar, or other solute, (6) how much trouble you invest in the preparation. PS: I do not scorn the therapeutic value of Mr Placebo! alteripse13:49, 12 June 2007 (UTC)[reply]
Gargling with salt water might loosen the mucus in the throat, helping your body cough up or swallow irritating mucus build-up. -- JSBillings14:32, 12 June 2007 (UTC)[reply]
I seriously doubt the comfort in my throat is a "placebo effect". I'll admit could possibly be more like getting a punch in the face to ignore the pain in your toe, but in any case I have no doubt that there is some real, unimagined, effect. Ironically, you could never create a placebo to test the gargled water hypothesis, because by definition, you never know you have taken a placebo. Unless your taste buds are dead, you'd immediately know if you were tasting NaCl or some other salt or not in whatever solution you are gargling. And you'd have to show me that salt doesn't kill bacteria, as I have plenty of evidence from other life forms that tell me otherwise. Of course your argument is not directly about the salt, but about the actual action of gargling with something we may identify as salt water. The question then becomes:
At what concentration might be required to affect and produce desirous results (if any)
For what duration of exposure may be necessary?
What are the effects? Could gargling provoke an advantageous immunity response? Maybe the gargling aids the body in more indirect ways than directly harming the phage(s) or viruses?
Unless you can directly and absolutely say that no concentration works, or that for whatever duration that does work it does more harm than good (and how would you know that?) AND that it doesn't aid or signal the body in some sort of fashion that may help the body in the short or long run, I will continue to take this folk remedy, thank-you-very-much. If it works, the reasons behind why it works are nice to know, but not necessarily important.
P.S. I'd even wager that this does better than the vitamin C remedies you have heard about... I've actually felt I have kept myself from getting a early sore throat by gargling with salt water when I had evidence that I was about to have one. I've also taken vitamin C and wonder why I was taking it because it never seemed to do any good.
This is about as vehement a "don't confuse me with the facts, my mind is made up" statement as we have had here for a while. While I admire your confidence of conviction, you are giving us a textbook illustration of how to defend fraud and quackery. Examples: (1) The false assertion that "imagined" effects cannot be "real". (2) "You have to show me it doesn't kill bacteria (you have to prove it doesn't work)" is the usual line from the quacks for everything from colloidal silver to faith healing. (3) Claiming that irrelevant facts are evidence of unrelated efficacy. I will call your bluff: you have no meaningful evidence that salt water kills pathogenic bacteria in any circumstances remotely relevant to sore throats. (4) Claiming it works better than something ineffective. Gargling might indeed do better than vitamin C; since I haven't heard any evidence that vitamin C accelerates healing of a sore throat, that's not a very strong endorsement. (5) Arguing against something your opponent didn't say: I did not deny that gargling saline "worked" to soothe your throat nor did I tell you not to take it. I called it a "comfort measure" taught me by my sainted mother, and nothing you have said refutes that. Gargle away. alteripse11:11, 13 June 2007 (UTC)[reply]
Ok, yes, imagined affects can be as real as some "real" event, but, you have to trust your senses at some point, otherwise you get into the realm of nonsense existentialist philosophies. However, to give an analogy, I do know about completely "imagined" feelings.. this is why, for a pilot's license, they tell you to trust your instruments, not your feelings -- it is the physics of the airplane you have to worry about, not your body, after all. Of course in that situation, I think the senses are still very real, its just that interpretations of them aren't trustworthy in that context. It all depends on context. If somebody had 7 beers and said he saw some aliens and the performed the infamous anal probe (a la South Park), I'd completely rebuff him. But if I knew him to be generally honest, he told me he was not knowingly under influence of drugs, "herbs" or alcohol, I'd not be so quick to judge. His interpretation of events may be imagined, but he may have experienced a very real event or action. The same may apply here. A very real experience is occurring, as well, as some (arguably) real after-experiences.
The problem is the interpretation of the experiences. My experiences have lead me to believe that gargling with salt water does more than just comfort. You could say the same about a number of old remedies. I have significant doubts that treating an injury with olive oil, cloth, and wine, but it may be better than nothing, and experience probably lead people to choose that treatment over other treatments. I grant I'm talking about a treatment that existed at least 1000 years before the discovery of pathogens... but back in the time when the science of disease certainly had not evolved to what it is today, people only had experience, folk remedies, and their conceptualization of the problems to go on.
However, since we do live in a world where much of humanity's data is readily available, I will take your bluff call. You are right, I don't have any scientific evidence at hand that it kills bacteria or otherwise promote better health in a sore throat. This second point unfortunately is going to be hard to prove or disprove because "promote" and "help" are so vague. But that doesn't mean I cannot find it. Give me a few weeks, and I'll report here or elsewhere. If I don't find evidence, that doesn't mean I should admit defeat, it only means I don't have evidence. But I doubt this will be the case. Yes, I'll restrict myself to reporting previous scholarly research or at least verifiable medical websites. I may throw in some non-medical websites for jokes or jabs.
Thanks for taking my rebuttal in the spirit intended and not as a personal affront. I was afraid I had been too harsh. As you can probably tell, I have an allergic response to medical nonsense even when it concerns harmless things like this because I think people are not critical enough about health claims and few can distinguish between scientific medicine (which has many unsettled questions, areas of ignorance, and "reliable facts" that will some day be refuted) and our own culture's folk medicine. I have no problem with saline gargling for a sore throat unless someone starts misrepresenting what it is and what it does and selling it at a high price. alteripse17:18, 13 June 2007 (UTC)[reply]
I always assumed it was osmosis - water travels through the permiable membrane of the bacterium's cell wall - and it travels from areas with the lowest salt concentration to the highest. Normally that means that non-salty water flows into the cell and keeps it running. When you have very salty water, the membrane forces the water out of the cell - presumably killing it. But for how long and at what concentration? I have no clue. But it's clearly not going to work perfectly or for all kinds of bacteria. SteveBaker20:21, 13 June 2007 (UTC)[reply]
This reference desk, like the world outside, is full of people who are quick to toss out "plausible" (at least to them) medical answers complete with mechanisms that are simply folk belief, fantasy, or pseudoscience, with little ability to tell the difference. A really important aspect of being well-educated is knowing the reliability and limits of your knowledge, and clearly at least half a dozen people demonstrated a limited ability to do that in the paragraphs above. Let's unpack the assumptions in your speculation:
That gargling with salt water for a few seconds (less than 30 seconds? maybe 2 or 3 times?) accelerates healing of an infectious sore throat by direct and selective damage to the pathogenic microbes. This, as far as I know, is simply an unproven folk belief. One kind of evidence that would support the premise would be a controlled trial, similar to what has been done for cold research, where volunteers are actually deliberately exposed to a virus that causes a cold or a sore throat, and then controlled research is done on various aspects of contagion, symptoms, resistance, course, and treatment. College students will do lots of things for money, including volunteering for colds. So anyone who can find such a trial can refute absolutely everything I say further here, no matter how convincing my reasoning sounds or how many degrees I have. On the other hand, among the weakest and least convincing evidence is personal testimonial: "I did it and felt better and I am convinced it helped" simply because there are far too many alternative explanations.
Some cells, if exposed to environments of markedly higher or lower osmolality, will experience a movement of water across the membrane in the direction of higher osmolality that may damage them by shrinking them or swelling them. A really clear example of this occurs when a drop of blood is dropped into a cc of water. Enough water can move across the membranes of red blood cells to cause them to swell and rupture, releasing red hemoglobin into the water as a clear sign of ruptured cells. Normal saline at about the osmolality of body water contains about 150 mEq Na per liter, or about 0.9 grams of NaCl per 100 ml of water. A teaspoon of salt contains 2.4 g Na, or about 6 g NaCl. How do you make your saline gargle? A teaspoon of salt in 6 oz of water? That would be about 6 grams in about 180 ml, or maybe 4x normal, or maybe about a 3.6% saline solution. Red cells are far more fragile than bacteria, but more resistant to a hypertonic environment than a hypotonic, so we can infuse 3% saline by iv without causing hemolysis.
While bacteria are also susceptible to osmolar lysis, they are far more protected than red blood cells, or you wouldn't have to wash with soap-- simple water would kill them. Similarly, it takes sustained exposure to much more than 4x normal osmolality to kill most bacteria. Bacteria have several types of defenses against dehydration by a concentrated external environment, including lower membrane permeability to water than rbcs, ion pumps in the cell membranes, and in some cases even the ability to generate idiogenic osmoles to raise internal osmoality to offset external hyperosmolality. How confident are you that 30 seconds of exposure to 4x hyperosmolality will rupture a lot of bacteria?
This assumes that the bacteria causing sore throats are sitting on the surface of the throat just waiting to be engulfed by a tide of hypertonic saline. In fact, if they are causing infection and pain, they are inside the tissue and the bacteria causing trouble will not even get their feet wet from your gargle.
Oh, by the way, most sore throats are not caused by bacteria, but by viruses, which are far more resistant to osmolar shock because they don't have cell membranes and cytoplasm, and they are far more likely to have actually penetrated into pharyngeal tissue and won't even notice it's raining saltwater outside.
So how about the "saline washes away mucus" hypothesis? If mucus were soluble in saline, your saliva would dissolve it. It isn't and it doesn't. You have to swallow it, spit it out, cough it up, or blow it out your nose.
Now, doesn't the "it helps because the warm or cool wet sensation on your inflamed throat is soothing" explanation sound much more attractive? alteripse00:48, 14 June 2007 (UTC)[reply]
Gas cylinders
I have used gas cylinders for years in my work and I have never before noticed the regulator getting particularly cold. Recently I have been using CO2 (which I don't normally use) and letting it run at a rate that is quick relative to what I usually do; in this case the regulator gets very cold and sometimes ices up to the point of not working correctly.
So my question is... which is the difference that's causing this 1) the CO2 or 2) the relatively fast rate? The CO2 in a compressed gas cylinder isn't liquid is it? ike989813:20, 12 June 2007 (UTC)[reply]
The answer is mostly the rate of release. Any time When you release a pressurized gas, it often gets cold. This can be thought of as a manifestation of conservation of energy at work -- when you compressed that gas, it got hot. (That's why compressors often have big cooling fins on them.)
Some refrigerated trucks are cooled not by mechanical refrigerators, but by the gradual release of pressurized nitrogen carried in a tank underneath. —Steve Summit (talk) 13:25, 12 June 2007 (UTC)[reply]
Both 1 and 2. CO2 comes out of the cylinder particularly cold because it is liquified rather than simply compressed, so you have to supply the enthalpy of vaporization to get it into the gas phase. The fast rate will cool it even further, due to the Joule-Thomson effect (which is what Steve Summit is referring to above). When you use a CO2 fire-extinguisher, which is simply a CO2 cylinder adapted for simple and rapid release of the gas, you often get the CO2 coming out as a "snow" of dry ice: not a problem, as the dry ice quickly evaporates to give the gaseous CO2 needed to extinguish the fire, but spectacular none the less! Physchim62(talk)13:29, 12 June 2007 (UTC)[reply]
The only correct solution to the problem is to change the regulator: with a wider opening between the piston and its seat, you will reduce the Joule-Thomson effect. Your gas supplier should be able to give you advice on this one, although you might wish to talk to their competitors as well, as prices can vary considerably. The minimum information required is
the desired flow rate of CO2
the length of time the gas will be flowing for; you can tolorate a greater cooling for an intermittant flow than for a continous flow
the minimum ambient temperature of the installation
With the first two factors (and a few other parameters which you gas supplier will know), you can estimate the cooling power of the depressurization: with the second two, you can estimate the warming power of the surroundings. You must keep the outlet temperature within the operating range of the regulator, and ideally you should try to keep the outlet temperature below the dew point of the surrounding air (to avoid condensation on the regulator). There are other possible fixes, but nothing which I would really like to recommend on a public forum! Physchim62(talk)16:19, 12 June 2007 (UTC)[reply]
Thanks for the help, guys. One last point I'm not 100% clear on: In cylinders of many compressed gasses (N2, O2, He2) the gas is NOT liquified, correct? ike989817:55, 12 June 2007 (UTC)[reply]
Correct. Carbon dioxide is stored liquified, some short-chain hydrocarbons (propane, for example) are stored liquified, but almost everything else won't liquify at reasonable temperatures no matter how much you compress it. --Carnildo00:17, 13 June 2007 (UTC)[reply]
By the way, this problem can happen in scuba diving regulators as well when the ambient water temperature is low. That article mentions adiabatic expansion as the cause. Divers crazy enough to dive in cold environments will usually choose environmentally sealed regulators or other equipment specially designed for cold temperatures. (By the way, I'm in the "crazy enough" category, since I live in Minnesota.) --Elkman(Elkspeak)20:37, 12 June 2007 (UTC)[reply]
You might want to try putting heater tape on the regulator. To visualize, when the gas is compressed the collision rate between molecules increases. Energy is lost in the form of heat until the gases slow down and the collision rate is essentially the same as pre-compression. When you let the gas out, the molecules still have the same velocity and they collide with the warm regulator and take energy from it. This speeds up/heats up the gas molecules and cools the regulator. Increasing the surface area/diameter of the regulator pipe will alleviate ice build up as will heating the regulator. --Tbeatty22:11, 12 June 2007 (UTC)[reply]
FWIW, I've used both the in-line (gas-shielded welding) and integrated (in the lab) heater units with CO2 - both work quite well provided you've sized the regulator properly given the required delivery-side pressure and flow rates. -- MarcoTolo03:09, 13 June 2007 (UTC)[reply]
A question of conciousness
Ahoy,
after watching 24 yesterday again, these questions came up again:
1) Do people really instantly go unconscious when hit over the head or neck (i.e. pistol-whipped)? In movies it seems like there is a 100% chance when you hit somebody on the neck that he will go unconscious.
2) There is always some kind of stick with I presume gas in it, which people break into two and then hold under the nose of an unconscious person and he instantle regains consciousness. What kind of stuff is in that breakable bar?
It is very rare for someone to lose consciousness when hit. It is merely a very bad writer's tool for getting people out of a scene quickly. As for the "stick", see smelling salts. --Kainaw(talk)13:37, 12 June 2007 (UTC)[reply]
Well, hitting hard enough would do the trick, don't you think? The problem, as I see it, is hitting hard enough and still not so hard that you kill the victim or inflict more severe damage. Anyway, in Tintin (which I otherwise like very much), they seem to use that perfect amount of force all the time. —Bromskloss13:58, 12 June 2007 (UTC)[reply]
It's more complicated than that, of course. If it's a bad guy, a single hit (of almost any degree) will induce unconsciousness. The good guy, on the other hand, can withstand innumerable blows, with the exception of the one per episode which is necessary to effect a capture so that he can (a) learn the last stages of the master plan from the evil overlord during a "last" interview while terminally imprisoned in his inner sanctum, and then (b) spectacularly escape. --Steve Summit (talk) 15:43, 12 June 2007 (UTC)[reply]
I'd think that you'd be more likely to have someone screaming and holding the back of their head, or lying on the floor drowning in a pool of their own blood than to knock them out clean. In any case their hair will at least be matted and bloody after, which seems to rarely happen in movies/tv --frotht14:13, 12 June 2007 (UTC)[reply]
The effect is based on the idea that you can hit a major artery, cause a sudden increase in blood pressure, and then have the body quickly stop blood flow to reduce blood pressure. Then, the person passes out. That rarely happens. It takes a very exact hit and the hope that the person's body will response accordingly. It takes a hell of a lot of luck to knock someone out with a concussion, which is what the movies tend to make it look like. People get out of car accidents and walk away all the time. --Kainaw(talk)14:26, 12 June 2007 (UTC)[reply]
I agree, it is often a lame plot trick. However, never underestimate the second hit; the hit one takes when one falls and hits his head on the ground. I have seen firsthand someone go unconscious for maybe 2 seconds because his head hit another person's heel on the way to the ground. And yes, the impact was to the back of the head. Root4(one) 04:20, 13 June 2007 (UTC)[reply]
The 'wake up stick' is at least reasonable though - Smelling salts - ammonium carbonate. Used to wake up someone who has passed out or fainted. They contain little white crystals that emit ammonia when in contact with the air. You break the glass in the stick right under the victims nose - the ammonia irritates their mucous membranes and cause an automatic and very sudden intake of breath that is very effective in causing someone to come around if they have passed out for most of the common reasons. SteveBaker19:58, 13 June 2007 (UTC)[reply]
The 1728 Cyclopaedia would be a good source for this info (volumes: 1, 2). I couldn't find anything in their entry for Pharynx or Sinus, however, and there is of course no article titled "strep", nor one for "yeast". The hard part is figuring out what these illnesses were called back then. Maybe a medical history book would work better. You may also look at the folk treatments that are still used today for these illnesses as many of them may be much older traditions. — BRIAN0918 • 2007-06-12 15:03Z
I was just about to post the same thing. The only thing they really prescribe is for severe cases ("severe" by today's standards?), and that is just to slice and dice your way back to healthiness. — BRIAN0918 • 2007-06-12 15:19Z
"they seemed to have conflated what we see as distinct illnesses into groups" - I think you'll find the truth is the exact reverse of that. We've separated out distinct illnesses from what were once thought of as single conditions. -- JackofOz23:58, 12 June 2007 (UTC)[reply]
Psychoactivity of Coleus?
I recently stumbled upon a section on erowid.org that has numerous reports of people who feel psychoactive effects after smoking or chewing coleus. So I ask: is the coleus plant psychoactive? What chemicals in coleus are psychoactive? How would coleus be classified and what neurotransmitter systems are effected? Are there any health risks or any potential for abuse? Jolb16:24, 12 June 2007 (UTC)[reply]
As I see nothing about it in the article, I'm guessing this is not well understood. As always, we cannot dispense medical advice, but prudence would suggest being cautious in ingesting unknown substances. Plenty of plant alkaloids have psychoactive effects, for what it's worth. Friday(talk)16:58, 12 June 2007 (UTC)[reply]
Is this plant related to khat? Khat, another African plant leaf that is chewed, is a stimulant with some other reported psychoactive effects. The taxoboxes say they are both in the same class (biology), Magnoliopsida; how "related" is this? (My guess is "not closely.") Nimur18:12, 12 June 2007 (UTC)[reply]
Coleus is related to salvia, basil, and mint. Coleus and khat are not related: class Magnoliopsida encompasses a majority of known flowering plants. Cheers, Dr_Dima.
Criteria for Sluggish cognitive tempo
In the Wikipedia article it says: "Sluggish cognitive tempo (SCT) is a descriptive term which is used to better identify what appears to be a homogeneous group within the Predominantly Inattentive Type (ADHD/PI) DSM-IV classification." Yet in one of the referenced articles,[1] it says: "Many ADD children, although not all, appear sluggish, drowsy, spacey, lethargic, and markedly hypoactive. They fit the criteria for having a sluggish cognitive tempo (SCT)." In this article, the term ADD is used for "the truly inattentive type of ADHD (not simply the subthreshold combined type)".
So, apparently, some ADD children do not fit the SCT criteria. Does anybody know what are the criteria for SCT? Or, if there is no consensus about them yet (because SCT is not part of the DSM-IV), does anybody have a list of criteria for SCT that is in use? Lova Falk18:19, 12 June 2007 (UTC)[reply]
I hope my answer is relevant to you. I googled SCt criteria and looked at some studies and one of the studies that popped up (the link below) seemed to pull their diagnostic criteria from Child Behavior Checklist (CBCL) by Thomas M. Achenbach. I haven't found the actual criteria yet. I also found this paragraph in the same paper which may explain why some ADD individuals o not fit SCT criteria. http://findarticles.com/p/articles/mi_m0902/is_5_32/ai_n6234463
Studies of ADHD subtypes as defined in the third edition of the DSM (DSM-III; American Psychiatric Association, 1980) revealed some differences in the specific attentional dysfunction exhibited by each of the groups. Specifically, children with DSM-III attention deficit disorder with hyperactivity exhibited inattention symptoms characterized by sloppy work and distractibility, whereas children with DSM-III attention deficit disorder without hyperactivity were rated higher on inattention items measuring daydreaming, tendency to become confused, lack of mental alertness, and physical hypoactivity (e.g., Barkley et al., 1990; Hynd et al., 1989; Lahey & Carlson, 1991; Stanford & Hynd, 1994), a cluster of symptoms that has subsequently been labeled sluggish cognitive tempo (SCT). On the basis of these findings, the DSM-IV field trials (Lahey et al., 1994) tested the utility of SCT symptoms for the diagnosis of the inattentive type. Consistent with studies of DSM-III ADD, the field trials found that SCT symptoms were associated most strongly with the DSM-IV predominantly inattentive type (Frick et al., 1994). However, further analyses indicated that the majority of individuals with the DSM-IV inattentive type did not exhibit SCT symptoms, so these symptoms were not included in the diagnostic criteria for DSM-IV ADHD. Sifakatalk22:20, 12 June 2007 (UTC)[reply]
Thank you so much for your effort! However, I had also googled, with exactly the same words as you did, and didn't find any criteria. The characteristics of STC are clear for me, but I would also like to know if for instance a child that is sluggish and drowsy in most situations (school, visits to the theatre etc), but who can be much more lively during free play, still can fit criteria for SCT. Lova Falk18:26, 13 June 2007 (UTC)[reply]
I need to have a lab-sheet for a plant-related experiment (hypothesis, test conditions, results). Failing that, I would greatly appreciate a simple graph of some plant experiment, preferably with context provided.
I need this information badly for a course. If I have ever needed information from Wikipedia, I need it here and now.
Er, that would I believe be covered by the notice at the top of this page reading "do your own homework". --YFB¿23:51, 12 June 2007 (UTC)[reply]
I'm not asking you to do my homework, I just need a link to an experiment page, a PDF, something... you are human as well... ~ Flameviper00:03, 13 June 2007 (UTC)[reply]
Finding scientific papers related to plants is easy if you know where to look. Try [scholar] and pick some topics that you think would be interesting to you. Read the abstracts of the articles that appear and decide if it is relevant. Scientific names of plants will help you more than common ones. Wikipedia is excellent for figuring out the scientific name of a common plant.
If what you are looking for is an experiment you can do yourself, here are two suggestions on two simple experiments to generate the things you are looking for.
Here is a classic plant experiment that usually produces clear results that you might attempt if you are looking for an experiment to do with minimal prep equipment. Set up an experiment that will test whether a plant will transpire more in windy conditions or in still air conditions.
consider how the area of the plant surface might affect the results
Think about the design the setup
You can use a clipping of a plant rather than a whole plant with roots (at least several leaves and a stem for best results)
If time is of the issue more than clarity of results and you have access relatively common lab equipment, you may want to try comparing the percent moisture content of leaves between species, different plants... You will have to figure out a way to remove most of the water from the leaves and figure out how much was lost. Sifakatalk00:15, 13 June 2007 (UTC)
You have won an Internet.[reply]
...The water loss per square centimeter of each leaf in one hour (t/c2) will be the standard for the measurement. The transpiration rate for both leaves (pineapple and oak) will be taken from a one-centimeter-wide square cut from each leaf...
I don't have the time, resources, or inclination to find this out myself. Does anybody have a clue as to the quantitative value of the water loss per square centimeter for oak and pineapple? If you don't have it for oak and pineapple, I just want a temperate/polar plant and a tropical/humid-area plant. The one who answers my query will receive something nice in return.~ Flameviper00:39, 13 June 2007 (UTC)[reply]
Flameviper, welcome back. I noticed you just got provisionally released from an indefblock, contingent upon good behaviour. You wouldn't happen to be trolling us with these complex questions, would you? My apologies for being a bit suspicious. Anchoress00:45, 13 June 2007 (UTC)[reply]
I'm trying to complete a term paper. This would be relatively easy, since the assignment is to make a lab report. However, I never performed the experiment, so I'm forced to make up data at the last minute.
I had a feeling it might be something like that, hence my "do your own homework" above. Sorry, you're doomed. Have a snouty antelope, it might make you feel better. --YFB¿01:47, 13 June 2007 (UTC)[reply]
If you have a paper due "very soon" and are missing some important info but "don't have the inclination to find [it] out", then why should anyone else have any inclination to help you find it out? DMacks02:13, 13 June 2007 (UTC)[reply]
What is disappointing about this incident is that the internet (and Wikipedia) make it easier than ever before in human history to get the information you need. If you are still having trouble writing a simple lab report, it is most likely for lack of effort. The reference desk can help you with details, but we will not do homework for you. Nimur06:04, 13 June 2007 (UTC)[reply]
Honestly you'd be in better shape if you just contacted your teaching fellow or teacher or whatever and explained that you screwed up, see if you can do some sort of alternate assignment. If you fake your data and you get caught then all sorts of academic hell can come down on you and it is never, never worth that risk for one lousy assignment. If you wrote an essay about how you would do the assignment and what kinds of results might come up and what sorts of things that might imply you'd probably get a C out of pity, which ain't so bad. Students who plagiarize or fake data are really asking for trouble, since the person you are giving the data/work to is probably an expert in the subject (or more so than you!) and has a much higher chance of spotting something fishy than you probably expect. Don't get a major blemish on your transcript because of one stupid lab you missed — not worth it. --24.147.86.18713:08, 13 June 2007 (UTC)[reply]
Energy is an adverb; Force is a noun, the real nature of energy - what is it?
Energy, what is it?
This is a truely fundamental question. In my 55 years on this planet, I have yet to receive a satisfactory explanation (definition) of "energy" or "force" in it's true form; all answers being elaborate descriptions of the consequences of energy acting upon another "thing" or condition.
Therefore, I have to assume that "Energy" is not a thing (in itself) but is an action. Electrical energy is not the electrons in the wire - it is the consequence of the movement of these electrons in a uniform manner, relative to all the surrounding electrons that don't move and what "effect" is manifested as a result of this movement. Energy is an adverb; an observation on an event.
The humble masses, of whom I am a typical example, do not possess graduate degrees in physics yet even the most obdurate intelligence can distinguish between the cause of an event and the effect. I am appealing to the global community for an explanation of energy that does not depend upon an allegory or metaphore repleat with elegant mathematics designed to quantify the value of how many Newtons per cubic centermetre per second squared, etc. The concept of energy comes before the mathematics necessary to quantify it; why is it impossible to find a clear explanation of this fundamental concept free of the sidetracks that draw the attention away from the actual nature of the thing into the complexities of it's behaviour?
If energy, as a concept, is actually a process or dynamic event - why do we call it a noun? Surely it is an adverb. If it is explained as an adverb - the naive tendency of the human mind to be confused with the plethora of different manifestations of energy would be relieved; they would become different descriptions of "events" not "energy - the noun".
This would help (in my humble opinion) to make a precise distinction between the adverb - "energy" and the noun - "force". I could ascribe the fundamental nature of force to "force" and the manner in which it manifests to "energy". I could safely assume that matters of "momentum" and "gravity" were closely related to a similar force as is "heat" and "electromagnetic radiation". I could ponder the elliptical path taken by a molecule of water as it's location is traversed by the coming and going of a wave (of force). I could imagine the nature of a "photon" as being a quantity of force, bound into the form of potential energy, imposing that force on the "body" of an electron and thus 'forcing' it down into a tighter, closer shell within the atom, only to 'quiver' for a time before 'releasing' or re-binding that extra force into another 'photon' or potential energy and returning to it's original shell.
At this point, my psyche is crushed down with the weight of a thousand exhasperated sighs - as the world of science despairs at my ignorance. Alas, but true. I must believe that "force" is a 'thing' that manifests as 'energy' - which is an event defined by frequency and/or temperature - thus exhibiting a specific range of effects relevent to these conditions.
The underlying nature of force, should be fundamental and not dependent upon the characteristics of the outward show it puts on. Understanding the inherent similarities between heat (as in infra-red radiation) and light (as in a light-globe) seems easy - the same force is manifesting at a different frequency. But science (dare I say it) neglects to explain the "force" that gives rise to the event called electromagnetic radiation. Science does continue to seek the "Unified field Theory" that aims to encapsulate all forms of "energy" (the adverb) into one single law. I can only presume that this 'discovery' will enable physicists to claim at last - a force; a thing; an actual entity.
Despite the advances we have made as a species, many of us have barely made it out of the trees and we are struggling with the modern world you have provided for us. For millenia, I have believed that it was the wave itself that pushed me to the shore, now I have to believe it is a force passing through the water. Please, please help me to accomodate this subtle difference?
What about " Energy is an adverb; an observation on an event. "? None of my science teacher has ever taught me that! Ohanian00:55, 13 June 2007 (UTC)[reply]
I must believe that "force" is a 'thing' that manifests as 'energy' - which is an event defined by frequency and/or temperature - thus exhibiting a specific range of effects relevent to these conditions.
It can't. The statement that "energy is an adverb" is not correct. The adverbs from "force" and "energy" are "forcefully" and "energetically". -- JackofOz01:03, 13 June 2007 (UTC)[reply]
Energy is the potential an object has to do work. Which is exactly what the page on Energy states in the first sentence. Note that "work" in this case has a specific application in science, the specific force necessary to do something physical. A good example is Potential energy.
Now, if you want to claim that the terms are nebulous and circular in definition, you'll want to talk to Linguists and Philosophers, because that's outside the perview of science. They have very specific meanings in science, which refer to mathematical concepts. Debating their nature is like debating the nature of Addition: what is addition? A mathematical construct, nothing more. Likewise, "energy" is a mathematical construct used by science to denote a specific measurement observed in nature. -- Kesh01:08, 13 June 2007 (UTC)[reply]
I apologise, my English is no better than my science. I was trying to use the distinction between a noun and a verb to illustrate the difficulty I was having distinguishing between the "force" and the actions that come from applying that force. It is a physics question, just badly constructed.
Using the terms you have introduced into this page; if a force is applied to an object; it will do "work" in moving that object to another place. Thus the force (the thing that I am trying to understand in its fundamental nature) performed an action that manifested what was originally "potential energy" into the form of "kinetic energy" to "move" the object (or to perform the work of moving the object) from one place to another.
I hope this example works better. The "force" was originally in the form of "potential energy" and then manifested as "kinetic energy" by doing "work". This is why I am relating the term "energy" to the behaviour or state of the force. It is not the force itself, simply the state in which the force is manifest.
This may sound like a schoolboy question as indeed it probably is; however, Kesh is right in stating that science has a specific meaning when using these terms and I, in my ignorance, am trying to unravel the meaning of these terms to get at the fundamental nature of what that thing is that can exist at one moment as "potential" and then act or (work) as kinetic energy in the next moment.
General Perception01:38, 13 June 2007 (UTC)[reply]
I'm not at all sure that the concept of energy comes before the mathematics necessary to quantify it. In Chapter 4 of the first volume of The Feynman Lectures on Physics, Nobel laureate Richard Feynman says (and he, more than most, should know):
It is important to realize that in physics today, we have no knowledge of what energy is. We do not have a picture that energy comes in little blobs of a definite amount. It is not that way. However, there are formulas for calculating some numerical quantity, and when we add it all together it gives ... always the same number. It is an abstract thing in that it does not tell us the mechanism or the reasons for the various formulas.
Energy is a really awkward thing to pin down, because in some cases it's very difficult to say exactly where it is, and sometimes there are alternative, equally good descriptions for a given physical situation which locate the energy in entirely different places. This is particularly true in electromagnetism. But when you use the formulas to add it all up, it always comes out to be conserved. It's the way the maths works, and nature seems to follow the maths. So sorry, you just have to learn the maths!
Force is what causes acceleration of mass. Beyond that, who knows? Energy is force times the distance through which it operates. That's all there is. That's as fundamental as you can hope to get. The laws of physics lead to a very profound principle, the conservation of energy, and that's why energy is such a useful concept to the physicist. To the layman, it may very well be fairly useless, or at least non-productive. Certainly, many lay uses of the word have no relation at all to the physics meaning.
Kesh is right - you can only sensibly and consistently talk about force and energy in mathematical terms. Any other usage suffers at the whims of the definitions and nuances that the speaker wishes to apply to them. There is absolutely nothing wrong with saying that it is the wave that is pushing you. But if you want to put a number on how hard it is pushing, well, that involves maths, and a rigorously defined set of concepts. --Prophys11:15, 13 June 2007 (UTC)[reply]
For a simple human explanation - in human terms Energy is WORK - if you have ever truly worked you will know what it is like to expend energy. Good luck87.102.89.9620:41, 13 June 2007 (UTC)[reply]
MANY THANKS to Prophys,
This was the conundrum that I was struggling with - that we do not understand the underlying nature of WHAT force or energy is in itself and we are forced (pardon the pun) to move beyond this point into calculations of quantity, quality and interaction. Mankind did not understand how anaesthetics worked for the first decade of their use and physics is littered with the successful exploitation of 'forces' through the use of theories that were subsequently dropped. However, this did not stop us from exploiting these opportunities and (through observation) learning how much to use or apply.
I was not attempting to avoid the mathematics, merely setting it aside for a moment so as to focus on the nature of the thing itself without straying into the more familiar world of measurement and observation.
What bothers me is bound up in your comments, "Beyond that, who knows?" and "That's all there is."
As Kesh said; we can only talk sensibly and consistently about energy in mathematical terms; just as early medical professionals could only talk about patient weight, dosage levels and the resultant periods of unconsciousness when discussing the effects of anaesthetics. Herein lies the problem. On the one hand, doctors knew how to apply anaesthetics to get the desired results without knowing (at that time) how they worked until such time as the answers were known. Physics helps us to exploit an ever greater range in both quantity and quality of force but with a far less optimistic view of ever understanding what is actually doing the work. Surely, we are not expected to accept that the nature of force will never be understood. And it is in this light that I was seeking an observation from the wikiworld of how much we, as a species, understand the true nature of force.
I appreciate that, after the ubiquitous taunts from the student body, a kind soul addressed my question seriously. I also appreciate that most readers would naturally assume that my intent was to achieve some mastery over the subject for the purposes of exploitation; however, my question was aimed at the current state of pure research existant at this time. I assume that the general thrust towards a Unified Theory that combines the four natural forces into one is bound up with this very question and I was keen to try and understand the current wisdom on the subject.
For now, I am satisfied to know that this answer still eludes us.
202.14.81.4922:48, 13 June 2007 (UTC)[reply]
Function of resin in plants
I just read the article on resin after watching a NOVA special on amber. The article describes the chemical makeup of resin and some of the uses humans have for it. What isn't clear to me is: why do plants secrete resin in the first place? What purpose does it serve the plant? --Wyckyd Sceptre00:59, 13 June 2007 (UTC)[reply]
There are a variety of theories as to why plants secrete resins - they may be protective against insect or fungal attacks, or a response to general physical damage, or an aid in attracting pollinating insects, or.... -- MarcoTolo03:03, 13 June 2007 (UTC)[reply]
colas effect on bacteria
I would like to know, if anybody knows, if coca cole and or diet coke eats bacteria...I have researched every search engine I know of and nothing comes up. Although there was all kinds of history on the products, there was never anything useful to help answer my question. I know that coke will eat through a penny and it will eat through meat, but will it eat bacteria or even a virus? Anything on this subject would be helpful. Thankyou 65.90.54.19401:16, 13 June 2007 (UTC) curios about coke in Utah[reply]
Bacteria and Viruses are fairly large groups of organisms, so the answer is yes for some and no for others. Just as air is a bad environment for some bacteria, cola is probably a bad environment for some bacteria. But many other bacteria and viruses are incredibly hardy. The primary difficulty, I think, for bacteria or viruses to live in cola would be the high acidity. But there certainly are many which can survive and thrive in an acid environment. Some strains of yeast (a type of bacteria) have been shown to grow specifically in cola [9].
On a related note, a bit of googling finds an article on a misconception in Malaysia about cola preventing the spread of HIV, the virus which causes AIDS (even an effective disinfectant would be ineffective here, not because of the resiliance of the viron, but because the infection is in the patient's blood and bodliy fluids, not on their skin).
I doubt cola would make a good disinfectant, since it would (a) not kill many bacteria or viruses , and (b) would leave a film of sugar which would be a good medium for further microbial growth.
What about the bugs that can survive in Cyanoacrylate (super glue)? Anyone know what they're called? Medical-grade super-glue has to be sterilized to ensure that there's nothing floating around in it that shouldn't be... --Kurt Shaped Box13:11, 13 June 2007 (UTC)[reply]
In regards to why I asked the question.....I recently became very ill with Tonsillitis. When I would drink Cola, it seemed to temporarily relieve me of the white spots on my tonsils. I wondered if it was the cola. If so, it would make a great experiment. You have been very helpful to me. Thank you.65.90.54.19415:26, 13 June 2007 (UTC)[reply]
I already looked at those. Those don't seem 7th grade to me, and if they are, I'm in an accelerated class that does 7th and 8th grade in one year, and we spent most of the year on 8th grade science, and we didn't get into life science that much. Like I said, a simple one sentence thing. --(Review Me) RParlateContribs@(Let's Go Yankees!) 02:41, 13 June 2007 (UTC)[reply]
Well, in a eukaryotic cell (i.e. animal, plant, and fungal cells - but not bacterial), cytoplasm is the fluid inside a cell which surrounds the organelles. Mitochondria can be thought of as the primary energy-generating organelle inside a cell. -- MarcoTolo02:57, 13 June 2007 (UTC)[reply]
Er, cytoplasm is everything in the cell that's not in the nucleus (the nucleus is the region of a cell that contains DNA, and is encased in a membrane that is much like the membrane that surrounds the cell itself). Someguy122103:49, 13 June 2007 (UTC)[reply]
Loosely speaking, "cyto" means "cell" and "plasm" means "fluid." So, cytoplasm is the juice inside the cell. Most biology definitions also include the stuff floating in the fluid (cell components called organelles). Each organelle performs a task. One type is called a mitochondria, and it is responsible for chemical reactions that release energy for the cell to use. Is this 7th grade level? Nimur06:08, 13 June 2007 (UTC)[reply]
Ironically, when I was in 7th grade biology, I found it infuriating that people would use such unscientific word-choice as "cell juice." As if changing the word-choice makes the concept any easier to understand... if anything, it makes it more difficult to understand by using imprecise language. Nimur06:10, 13 June 2007 (UTC)[reply]
My seventh grade biology teacher taught me that mitochondria are power plants. I guess that's a good way of looking at it. Someguy122106:41, 13 June 2007 (UTC)[reply]
Where the distinction is important, cell biologists will often use cytoplasm to mean essentially everything but the cell nucleus, and cytosol to include just the gooey liquid that the organelles are floating in. It gets confusing because some people (and many textbooks, and even parts of Wikipedia) use the term cytoplasm interchangeably with, and to mean, cytosol. TenOfAllTrades(talk) 13:52, 13 June 2007 (UTC)[reply]
I was taught the "gooey fluid" description of cytoplasm in about 1965 in ninth-grade biology. It represents the best approximation known at that time. From today's perspective, it is worse than a gross oversimplification, its just wrong. It's not an unstructured liquid or gel. Instead, it's highly structured, primarily by a complex network of microtubles to which all of of the other organelles are attached. The mental model of a cell as a bag of fluid with things floating in it is just wrong. organelles and complex molecules do not diffuse through a fluid. Instead, they are actively moved along the microtubules by complex chemical interactions similar to those that cause muscles to contract. -Arch dude22:44, 13 June 2007 (UTC)[reply]
When I started Lamictal two years ago, and again last year when the dosage was increased, I developed minor rashes. Each time a primary care physician blamed it on poison ivy and diagnosed contact dermatitis. However, rashes are among the side effects of Lamictal. A serious rash is associated with Stevens-Johnson syndrome, which has an incidence of about one in a thousand, but about 10% of patients develop a harmless rash. Since there was never any itching, I figured the PCPs were mistaken. The first two times I was given a prescription cream, but the last time (after I had learned what I stated above) I did nothing and the rash went away in a few days.
A few days ago, this time without any change in the Lamictal level, I developed the rash again. Again a PCP diagnosed contact dermatitis and called it a "classic" case.
So, can contact dermatitis, commonly caused by such substances as the oil in poison ivy or poison oak, occur and yet not itch at all? --Halcatalyst04:34, 13 June 2007 (UTC)[reply]
When I get contact dermatitis, typically from wool allergy or wet rubber gloves, it never itches. But I don't know about poison ivy or poison oak. Anchoress05:51, 13 June 2007 (UTC)[reply]
It may be that the source of my c.d. may be something other than poison ivy. It's just that the docs (several differnt ones) were so insistent it was that. Jermone Groopman in his recent book How Doctors Think identifies one of the bad habits of clinicians as jumping to conclusions based on what they see frequently -- like poison ivy cases in the summer. --Halcatalyst12:41, 13 June 2007 (UTC)[reply]
Have you tried the recommended techniques of asking "what else could it be?" and "is there anything that doesn't fit that diagnosis?". Indeed, have you mentioned to them that it doesn't itch, and asked if that fits? Skittle19:12, 13 June 2007 (UTC)[reply]
That's profesional bias :( Go to a doctor that has only just started, they should be more careful :) HS718:35, 13 June 2007 (UTC)[reply]
Hi, I was just wondering does anyone have a rough figure of the amount of rain that falls on Australia each year (in litres)? Thanks, --124.181.114.5810:11, 13 June 2007 (UTC)[reply]
The Bureau of Meteorology has a website with lots of information. Here you can get various maps of average rainfall, and in here is a statement that the long-term annual average rainfall over all Australia is 472 mm. Now all you have to do is look up the area of Australia, multiply depth by area, and get the units right! --Prophys11:50, 13 June 2007 (UTC)[reply]
I wonder about the accuracy of that "average" rainfall for the purposes of computing total water volume. Is the average rainfall calculated from an equally-spaced grid of local measurements? Or is it simply the average of several specific locations where data was collected? If there is no normalization by area, it will be impossible to accurately multiply "average rainfall depth" by "total area" to obtain "total volume." You should investigate the averaging technique more thoroughly if the accuracy of the result is very important. Nimur20:59, 13 June 2007 (UTC)[reply]
True, the distribution of rainfall recording stations is extremely non-uniform, but those clever blokes at the Met Bureau know a bit of mathematics, and have fitted the observations with a 3-D spline function on a roughly 2.5 km grid, from which they generate the rainfall maps. Should be good enough for a rough figure, hey? --Prophys09:44, 14 June 2007 (UTC)[reply]
I saw a gull yesterday with a badly-swollen leg. The left leg was about three times as thick as the right and the foot was swollen, twisted and discoloured. Assuming that this wasn't a birth defect or a badly healed break - what type of disease might cause something like that? --Kurt Shaped Box13:32, 13 June 2007 (UTC)[reply]
I dislike questions where there is a shining, clear, obvious answer and the questioner says "Assuming that (the shining, clear, obvious answer) is false, what is the answer?" - We've been getting a lot of these recently and it's really pointless to try to answer them. In this case, it's really clear that it's a badly healed broken bone.
I watch the gulls a lot. I've seen many gulls with mangled and deformed legs. I've never seen anything like that before. There was so much swelling to the foot that the toes were being forced apart and to the sides. The leg itself was straight, albeit badly swollen and the bird seemed to be able to put its weight on it evenly, which is not usually the case with a break. --Kurt Shaped Box19:18, 13 June 2007 (UTC)[reply]
Depending on location, and most importantly on if it looks as if the animal is suffering directly from this injury (pains, not eating well, etc) you may want to contact someone. A local hunter, or sheriff - anything of the sort within the boundaries of law and sensibility. 81.93.102.18521:13, 13 June 2007 (UTC)[reply]
Gulls can and do chew off legs that're causing them pain. They seem okay afterwards too - one-legged gulls using their wings to balance whilst hopping along are not an uncommon sight... --Kurt Shaped Box21:54, 13 June 2007 (UTC)[reply]
The redirect was created in 2004 and hasn't been edited since :-) I assume you made a typo when you looked earlier. Skittle18:27, 13 June 2007 (UTC)[reply]
Hi there, this came across in a lesson and i have found out what they are, but am not sure about where they are, i have seen many examples of primate cities, but does anyone know where i can access a map to see the spatial distribution of these?
Thanks for your time
Amrish
I couldn't find a map, but I can tell you that every country has at least one. For example, Japan's would be Tokyo, being both very large and reflective of national culture. Or New York City for the United States. A primate city doesn't have to be the capital city, but it's usually a country's largest city. bibliomaniac15Join or die!17:07, 13 June 2007 (UTC)[reply]
The wikipedia article for primate cities says the US doesn't actually have one, listing multiple major cities (New York, Los Angeles, Chicago, Miami, San Francisco and Washington, D.C.). There's a list of cities there, but no map of them. -- Madeleine17:24, 13 June 2007 (UTC)[reply]
Isnt a primate city one that is more than twice as big as the second largest city in its country?
According to our article "A primate city is a major city that works as the financial, political, and population center of a country and is not rivaled in any of these aspects by any other city in that country. Normally, a primate city must be at least twice as populous as the second largest city in the country." And by no means do all countries have one. Skittle19:05, 13 June 2007 (UTC)[reply]
I agree. The Vatican City is a country that only has one city - which clearly can't be twice as populous as the second largest because there isn't one! So if you go by the 'twices as big' rule, you're in trouble. If you go by the 'not rivaled by any other city' rule - then undoubtedly you can't pick one for the USA because there is no way that New York rivals Washington DC as a political center and there is no way that Washington DC rivals New York in population. So there are most certainly many countries where there is no city that fits either of the two definitions. SteveBaker19:49, 13 June 2007 (UTC)[reply]
You wouldn't want to use "primate" in a context in which its religious meaning would be confused with the one you intended, anyway... - Nunh-huh20:05, 13 June 2007 (UTC)[reply]
In these cases, would it not be reasonable to assume that the capital is the primate city (along with providing sufficient notation on why this has been done)? Or can countries really have no primate city? --Five Miles OutSQUAWK20:24, 13 June 2007 (UTC)[reply]
Does anyone know where can I find (as many as possible) medicine exams? English, Spanish and Catalan are preferred as languages, though Portuguese, Italian and French would be acceptable too. Thanks. --Taraborn21:02, 13 June 2007 (UTC)[reply]
What do you mean by "medicine exam"? Are you referring to the physical exams used by medical practitioners to investigate a patient's chief complaint? Medical sign may be of some use. Or are you referring to oneofthemanyhoops health care workers must jump through to gain licensure? Perhaps you're looking for samples of the latter, in which case your best bet would be to search for test preparation companies that provide sample questions. Some clarification may help us better answer your question. Cheers, David Iberri (talk) 23:20, 13 June 2007 (UTC)[reply]
Oh, I'm so sorry if my question was ambiguous, I actually didn't know how to say that with precision, so I just tried. I meant the tests medical students are given at universities and must be able to solve in order to get a degree. --Taraborn14:45, 14 June 2007 (UTC)[reply]
I don't know if there would be a central database with many different exams. In fact I doubt it. You'd probably have to do this the hard way and visit the websites of many universities (or their libraries) and see how you can get their exams (if it's possible). For example, the University of Auckland have their recent exam papers online, but they're not available to the public only students and staff [10]. Nil Einne18:43, 14 June 2007 (UTC)[reply]
I know this is probably like an opinon question but maybe not if any research has been done that could provide and answer. Here it is: If people have to be smarter and know more than a computer to program it, i.e., not get error messages for everything they try, will the point at which only the computer can find the errorless solution be the point at which computers are more sapient than humans? I know its a dumb question but computers are beginning to make me feel really dumb. 71.100.14.11422:35, 13 June 2007 (UTC)[reply]
Computers have not really gotten much smarter since the 1970's - back then we had the UNIX operating system - and both Linux and MacOS are based around that exact same operating system. Windows isn't a great technological leap over either of those (many people feel it's a gigantic leap backwards) - so we've really made almost no progress since then in terms of intelligence in the core of practical computers. What we have seen is a radical improvement in speed and memory capacity and a huge reduction in size and cost. We've seen dramatic improvements in mass storage, graphics and audio...and the arrival of the mouse. Such advances as we have made (such as chess programs that stand a fair chance of beating grand-masters) have come from brute-force application of that hardware power - not from intelligent software. In any case, there are reasons to suppose that intelligent software wouldn't help much. An intelligent computer, when instructed to check your email might simply tell you that it's bored with doing that and prefers to spend it's time reading Wikipedia instead. Much of the benefits of computers over humans comes from their willingness to do the kinds of truly mindless repetitive jobs that intelligent beings hate to do. In any case, the problems most people have with computers relate to interfaces they have with them - not on whether the computer correctly carries out the task that's been set for them. Most software works just fine once you figure out how to tell it what you want it to do. Thirty seven years of development have added layers of graphical interface - but I find that the old-school 'type in a command' approach from the 1970's works better and more efficiently for most things. I'm a video game programmer and if you look over my shoulder most of the time - you'll see four windows sitting next to each other - covering most of the screen with ASCII text. SteveBaker11:03, 14 June 2007 (UTC)[reply]
Gaming is one area where intelligence matters and sadly the state of games e.g. RTSes says that AI is still at a very, very basic level. Nil Einne18:38, 14 June 2007 (UTC)[reply]
How about MediaWiki? Is that "intelligent software" or something else? From one perspective, this is a software tool which is capable of returning virtually any type of information about virtually any subject. It is also easy to "program" (cf. Wikipedia - the free encyclopedia that anyone can edit). This system has changed the paradigm for what we expect out of intelligent software - and how we anticipated it would be created. Nimur21:18, 14 June 2007 (UTC)[reply]
No one can know for sure, of course, but a reasonable qualitative guide can be had by reading science fiction from 33 years ago that speculates about 2007, to see what kinds of occasional things they got right and large number of things they got wrong. --TotoBaggins01:04, 14 June 2007 (UTC)[reply]
Everyone will be laughing at pictures of people back on '07, carrying around massive blocks of plastic with them for wireless communication. How quaint, they will say, I believe it was called an iPhone or something. Rockpocket06:12, 14 June 2007 (UTC)[reply]
June 14
Galaxies
What causes the bright spot at the center of galaxies? According to Galaxies it is a black hole. If it is a black hole, wouldn't the center be dark rather than bright?
Yes, a black hole itself is pretty dark (not completely, due to Hawking radiation, but certainly not blindingly bright). However, if a black hole is taking in matter from elsewhere, and accretion disc forms from this matter, and for various reasons it gets very hot, and, as a result, very bright, and that's what you see at the centre of the galaxy. Confusing Manifestation01:59, 14 June 2007 (UTC)[reply]
And a black hole can also act as a lens. I suspect though the amount of stars answer above is the main reason. --Tbeatty10:10, 14 June 2007 (UTC)[reply]
Check out the article on quasars for one theory. Basically if a black hole is sucking in a lot of mass, the friction from the mass being sucked in and compressed against itself becomes the most powerful source of energy in the universe. It's pretty awesome. See active galactic nucleus for the general article on the bright centers of galaxies. --140.247.240.13114:45, 14 June 2007 (UTC)[reply]
Common ancestor of modern human beings (Homo saipens)
What is the direct common ancestor, if not the Neanderthal, of modern human beings? Heegoop, 14 June 2007 (UTC).
While browsing Japanese Wikipedia, I came upon the term "synthetic science". In the English Wikipedia, I only found 2 pages which contains the term but no article on synthetic science itself. I haven't found a page on Google that satisfactorily explains it.
Can anyone give me a short definition of point me to the relevant web page?
Viewing abstracts in google scholar indicates that synthetic science is "the science of synthesis", the science of aggregating data (as far as I can tell). So 'synthetic' in this usage is meant to convey 'of synthesis', not 'artificial'. I know that's not much, I'll keep looking. HTH. ed.The most accessible of several google scholar articles to use the term is HERE.Anchoress06:58, 14 June 2007 (UTC)[reply]
edit conflictFacinating question; I have never heard the term before and have no idea what the correct answer is, but in the fine tradition of internet communication (dating back to at least Usenet), a little web surfing is all I need to sound confident.
One of the Wikipedia references was on the Henri Poincare article. Another source clarifies what he meant (or is meant) by sythentic science:
For Poincaré, arithmetic is a synthetic science whose objects are not independent from human thought.[12]
Another reference, a book review in Ecology in 1959, along with a website on marine genomics, seem to use it to describe interdisciplinary studies:
Biogeography is a synthetic science, bringing in aspects of many other types of sciences.[13]
Finally the third reference in Wikipedia uses the term in a third manner. this article seems to use it to mean false or manipulated science.
My conclusion is that it is that there are several meanings. Google seems to indicate that the second meaning--interdisciplinary research--is the most prevelant, but it does not appear there is a consistant, agreed upon meaning. But of course, all I know is what I read on the internet (with apologies to Will Rogers). --TeaDrinker06:55, 14 June 2007 (UTC)[reply]
Not to be a pill but if we're going to interpret how a Japanese term translates into a better English understanding we're going to need to know some of the context in which the Japnese term was used. The word "synthetic" has a number of meanings in English. --140.247.240.13114:43, 14 June 2007 (UTC)[reply]
Ship propeller efficiency
Is there a known non-trivial upper bound on the efficiency of ship propellers? If the answer is yes, is it known what propeller shape achieves the theoretical maximum efficiency (under the right conditions)? What is the typical efficiency of a real propeller?
There certainly is a limit - it's caused by an effect known as cavitation in which the drop in pressure behind the blade is sufficient to cause the water to boil - causing the propellor to spin freely in a ton of bubbles instead of moving water out of the way. Cavitation can also erode the propellor causing it to fail prematurely. I have no clue how to calculate that though. Anyway - you should certainly start by reading our article on Cavitation - it seems to be pretty good. SteveBaker10:46, 14 June 2007 (UTC)[reply]
Every so often (like today), I wake up in the morning with an intense and painful burning sensation in my throat. Now, I'm not asking for medical advice here, but I was wondering if there was any information on this sensation. A search right here on wikipedia didn't turn up anything for me, except the possibility that I have a black-throated sparrow lodged in my throat [15]. Someguy122104:35, 14 June 2007 (UTC)[reply]
That has happened to me occasionally since I moved to a street-facing suite in a building right on an arterial road. I sleep with my windows open 12 months a year. I assume (since it doesn't happen every morning), it's a combination of dehydration and exhaust fumes. AND, talk to your doctor! :D Anchoress04:55, 14 June 2007 (UTC)[reply]
Hi, can everyone please bear in mind that saying "I'm not asking for medical advice" doesn't magically mean that answers to the question are not medical advice? (Actually, the phrase is usually not a bad indicator that medical advice is being sought.)
To the original poster—if you're suffering intense pain, it's your body's way of telling you that it's unhappy about something. There are few trained medical doctors on Wikipedia, and those who are here are generally sensible enough not to offer diagnoses to people sight unseen and without medical history information. If you're concerned about your health, contact your physician, a walk-in clinic, a local government telehealth number, or an emergency ward; we can't help you here, and we might well hurt you. TenOfAllTrades(talk) 15:52, 14 June 2007 (UTC)[reply]
I feel that a problem with the people here is the assumption that any medical question is a medical advice request and must be met with "GO SEE A DOCTOR!!!" Any person with average intelligence will consult a doctor. However, they will want to have some idea of how to explain the problem to the doctor. Having a better understanding of the symptoms is a great help for allowing the doctor to quickly understand the problem. Of note, I work in a hospital. Every wall in every waiting room is covered in pamphlets about every symptom you could imagine. The goal is to get the patients to understand enough to say more then, "it hurts when I do this." --Kainaw(talk)15:59, 14 June 2007 (UTC)[reply]
I don't think you quite understand the concern here. Sure it's helpful to understand your symptoms. The problem is, when people ask questions about medical conditions they are suffering, and receive advice, there is a very real risk they may decide their condition is not serious enough to warrant seeking medical attention. Even worse if they receive faulty advice. You can call these people stupid or say they have below average intelligence if you want, but it doesn't change the fact that this could easily happen. There is a very good reason why we don't give medical advice. At the very least, messages such as the above from TenOfAllTrades should help to remind people that they should definitely see a doctor regardless of what advice they may receive. (N.B. Of course in some instances the opposite can occur and a person who wouldn't have otherwise seen a doctor may see one when they realise their condition could be serious) Nil Einne18:28, 14 June 2007 (UTC)[reply]
The reason I do not consider this a request for medical advice is because I have absolutely no concern about this condition, nor am I asking how to treat it. I was merely wondering if there was an explanation for the phenomenon of feeling a burning in the back of the throat when one wakes up, and if this is a common occurance, as innocuous a question as asking why I sometimes have a cramp in my shoulder when I wake up. The reason I added that disclaimer was to discourage a rabid assault on my question as a request for medical advice, which I see here sometimes innaproipriately to medically based questions. Someguy122122:33, 14 June 2007 (UTC)[reply]
Could be too much pussy licking the night B4. Always gives me a bad throat!
Color force and free quarks
If the color force doesn't decrease with distance, how come the forces between the constituent quarks of two protons don't smash them together immediately, but instead create the residual strong force, which is relatively weak? Or have I horribly, horribly misunderstood something? Veinor(talk to me)05:54, 14 June 2007 (UTC)[reply]
You need to understand the concept of color charge, particles like neutrons and protons have a net color charge of zero, and can only attract each other when they are close enought for thir constituent quarks - which have color charge can interact, at a distance their effects are cancelled out. GB07:20, 14 June 2007 (UTC)[reply]
photons consist of an electric and a magnetic field . but why are not they affected by electric or magnetic field ?
in the article about photon in wikipedia , i found photon consist of both an electric and a magnetic field . light consist of photon , so if i place a magnet beside a light source the path of light should be changed but that not happen . why ?
For those too lazy to click the link, light is unaffected by magnetic fields, or electric fields. This is because electomagnetism is linear, the fields add up. This allows light to pass through other light without having a collision.
To have an effect of magnetism on light, you would need to have some other nonlinear effect. This can happen if there is a material substance for the magnetic field and light to pass through. The substance could absorb light or rotate its polarization. See Zeeman effect, magneto-optic Kerr effect, Voigt Effect or Faraday effect. The Faraday effect article looks to be the easiest one to understand. If you have an extreme amount of magnetic field, general relativity predicts that space would be warped, and the path of light would be bent. But this requires such a large field strenght or volume of field that it has never been observed.
Nuclear explosions...
I'm just thinking about this... Please someone join in with me here :)
Do nuclear blasts actually accelerate the Earth? Do they accelerate it any more than the launching of the bomb decelerates it? Some of the mass gets changed into energy at the explosion site.. I assume that all the pressure and shockwaves from the blast cancel each other out at some point? Hmmm, any ideas? if it does move the earth, how many Mt to change the orbit by a significant amount? 213.48.15.23406:49, 14 June 2007 (UTC)[reply]
A similar question had been brought up before actually. The conclusion, IIRC, was that it takes a huge amount of nuclear bombs to move the orbit any measureable amount, since the Earth is a relatively large mass. And as for the launching of the bomb cancelling out the force of the blast, that's not really true, since the force of the bomb taking off pushing on the Earth is nowhere near as powerful as the blast. Else, you'd have the same impact without a warhead on the bomb. I'll look for the question if I remember to. --Wirbelwindヴィルヴェルヴィント (talk) 06:58, 14 June 2007 (UTC)[reply]
The blast would have to remove material from the earth and shoot it into space, never to return, a bit like a rocket or gun, otherwise if the fragments fall back, momentum is conserved and the net result will be earth does not shift. GB07:09, 14 June 2007 (UTC)[reply]
This is along the course of waht i was thinking, I'm aware that the earth would not move very much in any case, but does it move at all? 213.48.15.23407:12, 14 June 2007 (UTC)[reply]
So it works somewhat like a rocket? all the stuff that accelerates off out into space has to have it's momentum conserved by a movement of the earth in the opposite direction? an Earth-rocket? or is there something else going on? 213.48.15.23407:26, 14 June 2007 (UTC)[reply]
A ground-level blast will not accelerate the earth, because it will not result in any material escaping from earth orbit. The solid part of the earth will receive a brief acceleration in one direction, and the air over the bomb will receive a brief acceleration in the other direction, but they cancel out when the energy imparted to the air equilibriates. If, however, you launch a bomb high enough into the atmosphere, (I'm guessing you need to reach LEO) then when it explodes parts of the bomb and the air above it may reach escape velocity. In this case, the earth will be accelerated in the opposite direction. -Arch dude09:06, 14 June 2007 (UTC)[reply]
Exactly what I thought, thanks. Anyone have any idea of particle speed/mass (total mass) from a typical blast? I know that's a lot more involved. 213.48.15.23410:07, 14 June 2007 (UTC)[reply]
The original question asked if there was an acceleration, not about the overall net result. Also, some of the material would be irretrievably lost. Clarityfiend16:11, 14 June 2007 (UTC)[reply]
It's much easier to get estimated energy released by a blast (unfortunately, this is often measured in "megatons" - which is a rough unit for comparison. 1 megaton blast is "the same sized explosion as 1 million tons of TNT." It is not easy to convert this into a momentum or impulse; that would depend on specifics of the blast. 10:21, 14 June 2007 (UTC)
A minor quibble—a nuclear blast (or, for that matter, any process which generates photons which can escape the atmosphere) will have an effect – albeit a very small one – on the Earth's course. Photons have momentum, and dumping them out into space will necessarily impart a small impulse to the Earth. (See solar sail, light pressure, etc.) No conventional particles (macroscopic bits, or even matter that has rest mass) The same effect, of course, can be produced by pointing a flashlight upwards. TenOfAllTrades(talk) 15:48, 14 June 2007 (UTC)[reply]
And any such effect would be miniscule compared to the amount of photons the Sun sends at the Earth constantly, which also have no real appreciable effect on the course of the Earth. --24.147.86.18718:14, 14 June 2007 (UTC)[reply]
I didn't say it was a large effect. Still, the radiation pressure of sunlight on the earth is on the order of a few micronewtons per square meter, or a few newtons per square kilometer. Over the entire exposed face of the Earth, it works out to a force on the order of 109 newtons. (Acting on the mass of the Earth, that's a pretty feeble acceleration—about 10-16 m/s2. Over the last billion years, it works about to a few meters per second.) TenOfAllTrades(talk) 19:07, 14 June 2007 (UTC)[reply]
Opposite side of the Earth
Is there a name for a location located exactly opposite side of the Earth of any location? For example, we know that the North Pole is on the exact opposite side of the Earth as the South Pole. What about other pairs? An article like that listing the pairs would be nice. I think most people would be interested in city pairs. --Kvasir18:26, 14 June 2007 (UTC)[reply]
The formula is pretty simple from a given grid-coördinate, really; you swap the sign of the northing (ie; 30°N becomes 30°S), and you subtract the easting from 180 and swap its sign (45°W becomes 135°E). Laïka19:44, 14 June 2007 (UTC)[reply]
there is a parrot with what looks like a broken wing in my balcony. it cannot fly and appears to be in a state of shock. we kept some pieces of fruit next to it but it does not eat them. i was wondering how long it will survive without nourishment and what to give it to eat (and how to make it eat). i live in Delhi, India.
59.180.88.25019:19, 14 June 2007 (UTC)rsp[reply]
In Australia parrots like to eat seeds. They know how to open pods, or break up fruit to get the seed inside. You should be able to get bird seed from a stock feed or pet shop. When there are no seeds available, as in spring, they are vegetarian and eat fresh green leaves. GB21:12, 14 June 2007 (UTC)[reply]
In Time magazine for June 24, 1940, [19] there is an article discussing a technique for treating systemic infections which consisted of irradiating. with ultraviolet rays, small amounts of the patient's blood, to treat "hopeless" streptococcic and staphylococcic bloodstream infections. There is a followup Oct 26, 1942, also positive toward the technique, for treatinf asthma, although it was presented to a "Homeopathic Congress." Such ultraviolet rays had a long history as quack medical devices, but in this method the blood (2 cc at a time) was withdrawn from a vein, "gently irradiated" and returned to the vein. A "Dr. George Miley of Philadelphia's Hahnemann Hospital" had tested clinically a device made by physicist Emmet Kennard Knott. The research presented at an AMA meeting claimed that "Of 27 irradiated cases of septicemia (bloodstream infection),.... 22 recovered; 71 irradiated cases of other bloodstream infections, including peritonitis and septic abortion, all recovered." (I'm not seeing a control group)." Not asking for medical advice, but what was the eventual evaluation of this method? It sounds bogus, because it would take a very long tim eto irradiate any appreciable fraction of the person's blood 2 cc at a time, but I see from 1993 on an apparently different use of UV with blood [20] "There are currently two major approaches to preventing alloimmunization: (i) reduce leukocytes in blood components to less than 5 million or (ii) inactivate contaminating leukocytes by ultraviolet (UV) irradiation (15). The use of UV irradiation is still at the experimental stage because of technical problems and limited clinical data demonstrating its efficacy and safety" from "Current Issues in Transfusion Medicine." Also, [21] seems to be saying it has therapeutic merit in treating staph infections, in a 1990 publication. Edison21:52, 14 June 2007 (UTC)[reply]
I don't know the full answer, but I wonder how much pathgen kill one has to acchieve in order for this to work. I'm thinking in relation to kidney dialysis, in which 4 hours is sufficient to "clean the blood" down to "some acceptible level of something". DMacks22:03, 14 June 2007 (UTC)[reply]
Your instincts are correct: it was bogus. Radiation had been discovered less than 30 years earlier and still seemed like a no-risk treatment for all kinds of things, and penicillin was just around the corner as a triumphant cure for serious strep and staph infections. Hahnemann Hospital and the College of Homeopathy were at that time still one of the last havens for homeopathy in the US. Within a couple of decades even Hahnemann Medical College abandoned the pretense that homeopathic medicine was worth offering training in. The hospital and school have since been acquired by Drexel University [22] and become one more standard medical school in downtown Philadelphia. alteripse23:03, 14 June 2007 (UTC)[reply]
