Wikipedia:Reference desk/Archives/Science/2007 August 8

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August 8

TRIGA Mark III

What specifically makes a TRIGA Mark III different than a Mark I and a Mark II? What level of enrichment of fuel would one installed in the 1960s have used? --24.147.86.187 00:44, 8 August 2007 (UTC)

I just know it was an itty bitty reactor, but people were very careful to step over (not in) any water leaking from it. Edison 02:45, 8 August 2007 (UTC)

Well, yeah, I get the basics of how a TRIGA works, I'm just curious was specifically a Mark III was. --24.147.86.187 13:20, 8 August 2007 (UTC)

This PDF document seems to have some information: [1] Check out page 51, which appears to provide the general differences between the different Marks. TomTheHand 14:25, 8 August 2007 (UTC)

That helps a lot, thanks! --24.147.86.187 01:36, 9 August 2007 (UTC)

Help finding news item on the plateau of cancer rates

I recently saw a news item stating that cancer rates have plateau'd, or perhaps even fallen, in recent years. I have looked, but I must not be googling on the right keywords. I don't care if I get a link to one of the news stories covering the topic, or the actual study. Thanks in advance. Anchoress 01:10, 8 August 2007 (UTC)

This Washington Post article might be what you're looking for. -- MarcoTolo 03:11, 8 August 2007 (UTC)

Here's a Boston Globe article on breast cancer rates, and a lung cancer review article from PubMed. -- MarcoTolo 03:14, 8 August 2007 (UTC)

Thanks MarcoTolo, for all the info. Anchoress 00:38, 9 August 2007 (UTC)

I'm assuming you're looking for US data. Fortunately the US does have a number of excellent cancer organisations; here's a useful report: [2]. Recurring dreams 13:12, 8 August 2007 (UTC)

Actually, I'm not particularly looking for the US, but any information is welcome, thank you. Anchoress 00:38, 9 August 2007 (UTC)

Dehydration and Gatorade

So, I work in a Pharmacy and got an interesting question the other day. Someone picked up an antibiotic and an anti-nausea medication. They then informed me that their doctor recommended to drink extra fluids since they ran the risk of being dehydrated. They asked me what they should drink and I said Gatorade. They then told me their doctor specifically said not to drink Gatorade. I thought about it a while and couldn't come up with an appropriate explanation. I told them juice and water. Why would a doctor not want a dehydrated person to drink Gatorade? Thanks Mrdeath5493 03:27, 8 August 2007 (UTC)

Gatorade has lots of stuff in it. Maybe one of the electrolytes or other additives interferes with one of the medications here (or some other medication not mentioned here) or the person is also on a high dose of one of those additives, or has some other condition rendering him/her sensitive to one of them. DMacks 04:36, 8 August 2007 (UTC)

You They need the fluids and electorlytes -- not the sugar. See Oral rehydration therapy, which includes a recipe for a proper fluid replacement drink, although it might not be as tasty as Gatoraid, it won't rot the teeth. --Mdwyer 05:14, 8 August 2007 (UTC)

If you read the article for Oral rehydration, therapy you'll notice that the recipes include sugar...Mrdeath5493 15:52, 8 August 2007 (UTC)

I'd bank on there being an order of magnitude less, though. I still hold on to my original claim. Gatorade is not recommended by doctors for rehydration, mostly because it has too much sugar. --Mdwyer 21:11, 8 August 2007 (UTC)

It looks like Gatorade is about 5% sugar [3], while the oral rehydration solution recipe is about 4% sugar, so Gatorade is higher, but not as much higher as I'd expected. StuRat 06:46, 12 August 2007 (UTC)

According to the Gatorade website FAQ it is recommended by doctors. Mrdeath5493 16:52, 9 August 2007 (UTC)

I wouldn't believe any testimonials coming from someone with such an obvious conflict of interest in telling the full truth as the company who is trying to sell the product. If you look closely, I'll bet the doctors only say it's better than soda or water, when you're dehydrated. This is true, but this doesn't mean it's as good as a proper oral rehydration solution. StuRat 06:46, 12 August 2007 (UTC)

Do you have a citation for what you found? Because I found this: One thing to keep in mind is that Gatorade is a sports drink and is not specifically formulated as an oral rehydration solution for persistent, severe diarrhea.[4] --Mdwyer 03:49, 10 August 2007 (UTC)

In the US, how about Pedialyte?

Atlant 12:32, 8 August 2007 (UTC)

Did you ask the pharmacist? You really shouldn't be asking random people on the internet about how to advise people with medical questions.... TenOfAllTrades(talk) 12:53, 8 August 2007 (UTC)

Most of the sources I see these days recommend diluting gatorade, etc. 1:1 with water, unless doing something really serious like a marathon, or something, because you don't need all the salts, etc. as much as you just need the water. Gzuckier 15:47, 8 August 2007 (UTC)

So, first of all, I'm pretty familiar with the basic concepts of medicine. I'm not asking this question so I can tell the patient. I'm asking because it makes no sense. I can see no reason whatsoever you would advise a dehydrated person not to drink something that was specifically designed to rehydrate. As for the notion that Gatorade has a lot of extra ingredients in it, it does not. It has water, sugar, salts, and coloring. A dehydrated person needs salts and, if they can't keep solid food down, they need the sugar. The Pharmacist was present for the entire conversation and she just laughed after the guy left, asking "why would you tell a dehydrated person not to drink Gatorade?" My general point is that the ingredients in Gatorade would be found in any other drink meant to rehydrate. So, you wouldn't just say Don't drink Gatorade; You would have to tell the patient to avoid X (X being whatever the doctor wanted the patient to avoid). I have considered every ingredient, but it makes no sense to avoid any of them while dehydrated. Mrdeath5493 16:05, 8 August 2007 (UTC)

Well, some medications can interfere with the removal of some salts, so it is possible that drinking Gatorade could lead to too high a concentration of something. But you are right that Gatorade isn't very specific about containing salts. Maybe the doctor just thought Gatorade was a waste of money in this case. Or maybe he was pissed that the Gators beat Ohio State in the Championship? Dragons flight 16:37, 8 August 2007 (UTC)

I think it's more the amount than the ingredients. Sugar and salt, along with anything else that gets in your bloodstream, causes cells to give up water through osmosis. I think what you are supposed to do is drink an equal amount of water and Gatorade (or water it down). The person might need the salt and sugar, but they need a higher proportion of water to go with it than Gatorade has. — Daniel 16:44, 8 August 2007 (UTC)

Look, Gatorade is designed to rehydrate. It is NOT going to cause hypernatremia or hyperkalemia. Sodium and potassium are absolutely essential to staying alive. They make your heart pump. The person in question was in danger of hypokalemia or hyponatremia, two conditions which result from being dehydrated. In fact, drinking only water after sever vomiting and diarrhea can cause the last two conditions. Also, the patient was on no other medications and the ones we gave them didn't interfere at all with salt retention/excretion. Mrdeath5493 17:17, 8 August 2007 (UTC)

Perhaps the patient had an unrelated (and undisclosed) medical condition, such as high blood sugar associated with type II diabetes, or the patient misunderstood their physician. I think if the pharmacist couldn't think of a reason why gatorade is a bad choice, a call to the MD to clarify their instructions would be helpful to the patient. --TeaDrinker 18:27, 8 August 2007 (UTC)

According to Medine there seems to be an issue with penecillin and tartrazine. Can't tell if it's strictly a cross-sensitivity issue, or if they both get processed by a common metabolic pathway that has some deficiency or bad downstream effect in certain individuals. Anyway, tartrazine is a commercial food dye, and just so happens to be in Gatorade Lemon-Lime. Maybe the patient is sensitive: the benefit of penecillin might outweigh its risk here but no reason to compound the problem with Gatorade when other drinks would suffice to rehydrate. DMacks 19:00, 8 August 2007 (UTC)

On further reading, tartrazine itself is used as a dye in some penicillin formulations. So either patient is known to be sensitive or just a general precaution against too much of a certain irrelevant-to-therapy additive that is known to be troublesome for some individuals. DMacks 19:38, 8 August 2007 (UTC)

"Gatorade is designed to rehydrate." this says that it is designed to keep sugar levels up during prolonged exercise. If you aren't exercising, and all you actually need is fluids, then you should NOT be using a sugary sports drink. Maybe you should also read about treatment for cholera. --Mdwyer 21:11, 8 August 2007 (UTC)

Ok, why should you NOT drink a sugary sports drink? That is why I started this thread; I'm simply asking why not. I understand everyone's opinion, but that isn't helping. The simple fact is that Gatorade has an osmolality very close to our blood and is essentially easily drinkable IV fluid. I honestly cannot think of another commercial product that would be better for rehydration. I realize that it has a lot of sugar, but when you are so sick you can't eat, sugar dissolved in water is exactly what you need (along with electrolytes of course). Gatorade would likely be your last option before beginning IV rehydration. Ideally the solution would have less sugar, but oh well. The amount of sugar in Gatorade doesn't affect rehydration negatively. By the way, can we please assume this patient did not have a 1 in 1000 condition or diabetes (because they didn't). Mrdeath5493 05:36, 9 August 2007 (UTC)

• Why not? Well, now your patient traded Dehydration for Hyperglycemia. Of course, it is true that the patient's dehydration would be cured.
• Drinkable IV fluid? What kind of IVs do they use where you're from?! A plain saline solution has no coloring, flavoring, or sugar.
• Another commercial product; how about Pedialyte which was already recommended or Ceralyte?
• When you are so sick you can't eat SEE A DOCTOR.
• No, Oral rehydration therapy would be your last option before IV rehydration. --Mdwyer 13:47, 9 August 2007 (UTC)

Let's face it, nobody here actually knows why this particular professional gave this particular piece of professional advice to this particular patient. We can what-if forever, you can keep feeding us new details that you didn't mention earlier, we can brainstorm a zillion reasons and hypothesize about whether the issue in the prescriber's mind is Gatorade in particular or "sugary sports drinks" in general or whatever else. We can keep arguing about whether something is "not the best solution" vs "a dangerous thing to do" for this case if you like. You say "Ideally the solution would have less sugar", so you clearly recognize that the sugar load is higher that desired, so why wouldn't the doctor suggest steering clear of something that has this drawback...it's not like the choice is between Gatorade and no-fluid-intake. Only one person knows the answer, and it's already been suggested that you go ask him/her. Please do and let us know what the actual answer for this actual case is. DMacks 06:33, 9 August 2007 (UTC)

Clearly, the doctor in question had once had an enormous cooler of Gatorade dumped on his head after the successful conclusion of a sporting event ("as seen on TV"), and he's still pissed-off about it.

Atlant 13:28, 9 August 2007 (UTC)

Sorry, but hyperglycemia is laughable. As long as the patient has a functioning liver/pancreas, it wouldn't last too long. And when I said drinkable IV Fluid, I was referring to Lactated Ringer's solution. Gatorade doesn't have that much sodium. I have looked at Ceralyte and can find no major difference between it and Gatorade. The weakest mix of Ceralyte has 40g of carbs that is to be mixed into 7oz. of water (more than Gatorade...). Of course the healthy liver/pancreas example applies here too, so as long as they aren't diabetic then is no real risk of hyperglycemia. Mrdeath5493 16:37, 9 August 2007 (UTC)

I'm not laughing. In fact, the article says that hyperglycemia can cause feelings of sadness. Oh, the irony! Compare the calories in Gatorade to Ceralyte. And LR doesn't have any sugar in it, either.

But I can see you won't agree with me. Will you at least agree to consult a doctor if the opportunity arises? Gatorade /will/ work, and probably won't kill anyone, but it simply isn't recommended when treating dehydration. --Mdwyer 17:17, 9 August 2007 (UTC)

Just for clarification for anyone reading this debate, Gatorade turns out to be an excellent way to rehydrate orally.

Concerning consulting a doctor, I know several doctors personally seeing as how I worked for them for 4 years (not to mention the doctors (M.D.'s) that teach at the medical sciences school I attend). Their general consensus was that the idea that Gatorade isn't suitable for oral rehydration was ludicrous excepting children ~5 and under (whose diarrhea may rarely be worsened by fructose). I'm sorry Mdwyer, but if Gatorade isn't suitable for rehydration, the burden of proof is on you to show why. That is the only thing I have asked for; and no one can give me a good reason. Worrying about depression from hyperglycemia is incompetent at best (seeing as how the patient would be so so sad to be alive). Oh, and doctors don't worry about long term tooth health when trying to keep a patient alive either. Just a matter of priority, I'm sure. Mrdeath5493 06:56, 10 August 2007 (UTC)

I'm sorry, but "Worrying about depression from hyperglycemia is incompetent at best (seeing as how the patient would be so so sad to be alive)"? Surely you know a little more about depression than that? Skittle 22:35, 10 August 2007 (UTC)

Ah, so you DO agree with me that Gatorade is less suitable as a medical treatment because of the excess fructose. It's about time. --Mdwyer 14:12, 10 August 2007 (UTC)

While Gatorade may be appropriate (other than the dye and being slightly too high in sugar) for someone who is not eating any food (as during an athletic event), it isn't appropriate, IMHO, for someone who is eating normally. The reason is that most of the salts, sugars, and minerals needed in the diet are already provided by solid foods in the typical Western diet (and, in many cases, far more of these are consumed than needed), so drinking Gatorade provides an excess of these nutrients. The advice to dilute Gatorade may apply here, or perhaps water alone is sufficient, if the solid food diet provides all the nutrients needed. I myself prefer water with lemon juice; it's tasty, cheap, and quite healthy (for those of us who already get more than enough sugar calories without adding more by drinking Gatorade). StuRat 07:07, 12 August 2007 (UTC)

Hyperglycemia won't cause long term depression...

Bird crap

Serious question. I leave my car at home most days and walk to work. The car's parked under my carport, but almost without fail when I get home a bird has left a little gift for me on the car. It's nearly always on the bonnet on the front passenger side, or thereabouts.

OK, at first I didn't worry too much, but this has been going for about a year now. I doubt it's doing my paintwork much good, and quite frankly I'm sick of cleaning it off. I think the bird may be an Australian Magpie, but am not entirely sure. There's nothing above the car that the bird would land on, so I assume it is landing on the car itself to do it's business.

Any suggestions for why the bird may be targetting my car, and what I could do to discourage this behaviour? Thanks for any serious responses. --203.164.131.237 14:17, 8 August 2007 (UTC)

An Australian Magpie, eh? Well, if you were in Australia, I'd say that it was just bad luck. But as you live in Norway, I think you should contact an excorcist and start praying really hard... Myles325a 03:16, 9 August 2007 (UTC)

Could it be perching or sleeping in your carport? Sheltering from the wind or bad weather? Lanfear's Bane

Buy a car cover. SteveBaker 14:50, 8 August 2007 (UTC)

Birds dont land to poo. It seems quite possible that the bird drops its bomb whilst flying towards you carport's open end and then pulls the stick back to avoid crashing into it. The bomb will continue with parabolic trajectory and hit your car. Maybe its nesting in your eaves?

Solution?

• move your car out of the flight path
• get rid of the nest
• shoot the bird.

--SpectrumAnalyser 15:18, 8 August 2007 (UTC)

While they don't land to poo, they do poo while sleeping...

(That means these birds sleep while flying...Myles325a 03:09, 9 August 2007 (UTC))

While it's doubtless true that birds don't need to land to defecate, I can assure you that at least one sun conure prefers to be perched to poop and tries very hard to do all her pooping in a very few well-approved places. I'd look up and see if there are convenient perches in the carport; maybe you need those nasty "wires sticking up" things that are used to discourage pigeons.

Atlant 13:34, 9 August 2007 (UTC)

If it is sleeping in the carport, it may be leaving a present while it is asleep. One thing I've seen is that birds tend to target shiny surfaces. It may have even been on Myth Busters. An experiment covered the floor an aviary with different surfaces and all shiny surfaces were targeted more often than non-shiny surfaces. This is a possible explanation for the reason freshly-waxed cars are targeted more often. -- Kainaw^(what?) 17:02, 8 August 2007 (UTC)

If they are indeed roosting in your eaves, there are large spikes you can purchase that you can put along them for this very purpose. Another thing that may be worth trying is one of these ultrasonic devices, but I'm sceptical as to whether they work or not. Angus Lepper^{(T, C, D)} 17:20, 8 August 2007 (UTC)

Maybe it's a very clever and tidy but lazy bird that has figured out that if it takes a crap there it always gets cleaned up after him. :) DirkvdM 06:33, 9 August 2007 (UTC)

Thanks for the people that attempted a serious response:

1. Hmm, who said I lived in Norway; let me check...no, it's definitely Australia.
2. No, definitely not perching or sleeping in the carport. As I said originally, there's nowhere for it to even land above the car, much less sleep. And as I also said, it's been happening for about a year now, so it's not just a matter of the bird/s avoiding bad weather.
3. Car cover, good suggestion, had thought of that myself, but rejected it on several other counts.
4. I don't know what this talk is of birds not pooing while landed, and pooing while asleep. Where do those ideas come from? And no, not nesting in the eaves either, or anywhere nearby for that matter. And I do not want to shoot, poison, stab, strangle or drown the bird.
5. Unless this bird is a somnambulist it's not pooing while asleep (and, incidentally, why would sleeping birds target shiny surfaces?). Thanks for the idea on the shiny surfaces, though not sure where I can go from there.
6. Nope, not nesting nearby. Sorry, AFIC ultrasonic devices are a scam. Perhaps I could fit spikes to the car? Thanks anyway.

Incidentally, the reason I suspect it may be a magpie is that I saw one land on the car in the very spot a couple of weekends back when I was home (yes, it landed, and no, it wasn't asleep (!)), but I shooed it off before it could act. So, any other suggestions? --203.164.131.237 13:36, 9 August 2007 (UTC)

Shooing the bird away is probably a very bad idea. Many animals (humans included!) have an instinctual tendance to pee and/or pooh when scared. This is a sensible reaction (especially in birds) because it reduces body weight - with allows a faster get-away from whatever is scaring them. Birds in particular need to lighten themselves in order to fly more efficiently. So, no - don't even think of bird-scaring tactics. SteveBaker 14:32, 9 August 2007 (UTC)

Some birds move their fledgling's Fecal sacs away from the nest, so it might be more intentional than you think. -- JSBillings 17:06, 9 August 2007 (UTC)

It's quite possible that birds poo when approaching or leaving the nest. Like most people take a crap in the morning, birds probably do too, but only when they leave the nest. So maybe there isn't a nest above the car, but nearby. Or maybe, if it's a magpie - they collect shiny objects, right? But it can't collect the car, so maybe that pisses it off and it takes revenge in this way. :) DirkvdM 06:41, 10 August 2007 (UTC)

You may only have to annoy or scare the bird once to get it to break the habit of landing there. Some suggestions:

1) Put something scary there, like a fake predator, such as a rubber snake.

2) Put something annoying there, like sand. It probably won't like the feeling of sand grains on it's toes.

3) A more expensive solution would be to mount a motion detector pointed at the spot, triggered to spray water at it when motion is detected.

If this just makes it move to a new spot on the car, do the same thing in that spot, as well, until you persuade it to go elsewhere. StuRat 13:58, 12 August 2007 (UTC)

Microwave Oven Longevity

Hello. I have a 10-year-old (or older) microwave oven. How long can a microwave oven be harmlessly used? Please cite reputable sources if possible, preferably Canadian (e.g. Canadian Standards Association, Technical Standards and Safety Authority, etc.) Thanks in advance. --Mayfare 14:54, 8 August 2007 (UTC)

Hers a link to start you off. [5]. Googling 'microwave oven safety Canada' gives many results.--SpectrumAnalyser 15:01, 8 August 2007 (UTC)

[This 2000 report http://www.hc-sc.gc.ca/ewh-semt/pubs/radiation/microwave_ovens-micro_ondes/index_e.html] (follow the link to the PDF) is quite illuminating. In a survey of 103 used microwaves in ages ranging up to nearly a quarter century, only one twenty-three-year-old microwave failed to meet the Health Canada regulations (and even then wasn't leaking to a level likely to cause harm).

Appreciable microwave energy should only be able to get out if the microwave cavity is damaged (serious dings and dents, particularly around the door, or tears in the window mesh) or if the door interlocks are defeated. (The door interlocks are required to be failsafe, but in principle could be compromised by deliberate tampering.) TenOfAllTrades(talk) 20:22, 8 August 2007 (UTC)

Expanding on what TenOfAllTrades has already said, modern microwave ovens all use a "choke seal" that depends on maintaining certain mechanical clearances between the door and the oven itself, rather than some sort of gasket material. As such, the door's "microwave seal" should last essentially forever if the door and the adjacent sealing surface are not mechanically damaged and the door hinges and latch don't grossly shift position. A careful visual inspection should tell the tale.

I personally have no qualms about operating reasonably old microwave ovens; as it turns out, both of mine are hand-me-downs, one from my father and one from the previous owners of our house. I'd estimate they're both 15 years or more old; my dad's is on its second magnetron but otherwise running fine. And I, in turn, handed-down an even-older oven to another person when I acquired these; I had no qualms about that oven either or it would have become a "take-apart" experiment.

Atlant 13:25, 9 August 2007 (UTC)

We had the same microwave for 30 years (Litton brand). While it worked until the end, it gradually lost power, and, finally, was only suitable for warming coffee. StuRat 06:19, 12 August 2007 (UTC)

Blood Plasma Discolouration

I know we are not supposed to ask for medical advice, however, this is more of a personal enquiry than a direct medical question. I, as a phlebotomist, deal with people's blood on a regular basis, and there was a sample of blood I took and 3 or 4 days later, I looked at it and the plasma, after seperation, was a darker brown colour than the usual straw colour. I have no intent to try to treat the patient etc, but am curious as to whether this is any indication of infection etc, or just that the blood had been lying for a while. Christopher

(Guessing now) Lysis/Cytolysis of some of the red blood cells?

Atlant 13:17, 9 August 2007 (UTC)

Safe pesticides for use near Florida mangroves

I have a large amount of mangroves outside my house in Florida, and there seem to be many bugs not only living in them but also eating them. These are really nasty bugs. I was wondering if there is any safe type of pesticide to use against these bugs, but wont harm the mangroves. Thanks Alot

My biggest concern would be that the pesticide would end up in the water beneath the mangroves and do who-knows-what damage to the aquatic ecosystem. SteveBaker 22:39, 8 August 2007 (UTC)

Yeah thanks I thought of that right after I posted the question. Probably its better to just let them be.

Yeah - unless there is a natural predator for these beasts that you can somehow attract to the trees. You might try a company like Buglogical who will sell you various predatory critters for this kind of thing. SteveBaker 19:47, 9 August 2007 (UTC)

Voss and Fiji brand water

My friend says that water sold in the Voss and Fiji brands are so expensive because the water has never "touched the atmosphere". Is that even possible? Can water form in large quantities (enough to commercially packaged and sold) which has never come into contact with the Earth's Atmosphere?

It's possible (actually, it borders on trivial: take a vacuum chamber, fill it with hydrogen and oxygen and light the blue touch paper — bang, instant water) but I'm almost certain that they won't manufacture it like this (it would require considerable effort to do on a sufficiently large scale, and any natural water will have touched the atmosphere at some point). Apart from anything else, it's virtually irrelevant whether it's touched the atmosphere or not (i.e. if they do manufacture it, it's a gimmick). Angus Lepper^{(T, C, D)} 20:15, 8 August 2007 (UTC)

(I bet your oxygen touched the earth's atmosphere at some point!)SteveBaker 20:24, 8 August 2007 (UTC)

Obviously, yes. If we're going to be pedantic, however (not that it's a bad thing), the water wouldn't. However, what your point does go to show is the silliness of the claim. Angus Lepper^{(T, C, D)} 20:53, 8 August 2007 (UTC)

But the problem is (for the uber-pedant!) that not all of the oxygen would turn into water at the precise same instant - so at some point in the process, water would be intimately mixed with yet unreacted oxygen - which was (presumably) part of the atmosphere. I suppose you could electrolyse some water - then react the resulting oxygen/hydrogen mix to make 'new' water that had only touched hydrogen and oxygen that came from the 'old' water...but it's a bloody stupid thing to do - and I guarantee they aren't doing it! Yeah - it's a silly claim. SteveBaker 22:10, 8 August 2007 (UTC)

If that was why they are so expensive, wouldn't they make it a selling point? In which case you would see it prominently on the bottle. Also, all water will have come into contact with Earth's atmosphere at some point. I suspect your friend is pulling your leg, since it seems such a bizarre thing to come up with. Skittle 20:14, 8 August 2007 (UTC)

Yes - it's a ridiculous claim. If you take it literally enough - it can't be true. If you relax and don't take it too literally (eg it doesn't touch the air from the time they pump it out from some underground aquifer until you open the bottle) - then it's a rather useless purity claim. Either way - we shouldn't care. SteveBaker 20:24, 8 August 2007 (UTC)

It isn't a big deal. Most residential well water could make the same claim. The wells are generally not open to the air (and if they were, the water's safety wouldn't be as easy to assure), and go from pump, to sealed pressure tank. That water only hits open-air when it comes out of the faucet. --Mdwyer 20:57, 8 August 2007 (UTC)

I think my biggest question is, can water form in rock? Water had to have formed at some point in the atmosphere. I just assumed that at one point water formed in the surface and gradually trickled into something like an artesian well where it lay for a long time.

You can certainly get water out of rock - if it's the right kind and you chemically treat it in the right way. But most of the water that's on earth right now mostly came from comets and icy meteors. (See The Hadean eon). However, water circulates from oceans to sky to rain to soaking-through-rock-into-basins - it's pretty unlikely that any of it has stayed buried since the early earth - if for no other reason than that continental plates move around, get subducted under the surface and melt back into the mantle. Underground aquifers that stayed around for more than a few tens of millions of years would be gone for good! So the idea that these guys are selling water that's been underground since the formation of the earth is totally bogus! SteveBaker 14:26, 9 August 2007 (UTC)

I've been watching this for too long, and I have to say that the people who have posted above me have no idea what they're talking about. What water has encountered in the past is actually incredibly significant. Oh wait...Someguy1221 06:22, 9 August 2007 (UTC)

that would be a new one for the list: http://www.chem1.com/CQ/gallery.html Gzuckier 17:06, 9 August 2007 (UTC)

I think the selling point of Voss is that it hasn't touched the atmosphere since the industrial revolution began. 147.197.230.174 09:13, 9 August 2007 (UTC)

They are so expensive because there are enough people in the world daft enough to pay so much for them. DuncanHill 13:42, 9 August 2007 (UTC)

Fiji water is tapped from deep volcanic rock. It goes straight into the bottles without ever touching the atmosphere. It does, however, touch plastic all the time it's being shipped over to wherever you live. Tastes very smooth and Queen Latifah swears by it. Vranak

Mmmmm - mould release agent - delish! SteveBaker 00:14, 10 August 2007 (UTC)

OK so here's another related question, my friend now is specifically saying that water formed in the rocks and thus never touched the atmosphere. I just can't wrap my mind around that. ie: you can't have 2 stray hydrogen molecules combine with an oxygen molecule to create water in something like a rock bed. I mean rock in my mind is very impermeable, not being a geologist, I can't say for certainty but I did take 1 year of geology in university and I just can't see water seeping through anything other than talc.

Are we smarter now?

What evidence, if any, is there that human beings are more intelligent now than, say, 5000 years ago?

That length of time is short for biological evolution. Cultural evolution has certainly made the human race far more capable technologically and in other ways; but are we more intelligent? --Halcatalyst 20:09, 8 August 2007 (UTC)

You might take a look at Flynn effect. And you might think through what you mean by "more intelligent." As you note, it is probably (though not surely!) too short a time frame for much of a genetic effect. However the improvement in nutrition over the last 1000 years alone has changed the expression of traits like stature quite radically, and it is likely it would have changed the expression of intelligence as well. That is, the potential intelligence of humanity probably has not changed over 5000 years, but the expressed intelligence has probably risen greatly, owing to better nutrition and other developmental factors (fewer childhood diseases, etc.). On the latter see Health and intelligence. --24.147.86.187 21:20, 8 August 2007 (UTC)

I think that there could be significant movements in intelligence over 5 thousand years, speaking genetically. After all, human settlement of the world extends over 40 thousand years, so genetic variations between Australian Aboriginals, Chinese, Caucasians etc occurred over this time frame. 5,000 years is one eighth of this, but that is a significant fraction. Most commentators on evolution tend to overemphasize simple survival traits. In my view, beneficial traits in human SOCIETY are fixed by sexual and cultural selection. In other words, in an oral society, someone who can speak well has a better chance of doing well, and thus being desirable to women, thus bettering his chances of passing on DNA to subsequent generations. Same for cultural effects on evolutionary trends. Thus, it is likely that markers for intelligence have been enhanced in human history, faster than many might suppose. This being said, people 5000 years ago would not stick out today as being particularly dim. It is difficult to say. 58.168.64.117 01:34, 9 August 2007 (UTC)

Except that with humans it is very rare for someone to be so stupid that they can't reproduce. In fact, as many 19th century theorists pointed out with great fear, the structure of Western society actually encourages the very smart not to reproduce as much (harder to have a career, etc., with 10 kids), while at the same time extreme reproduction has always been a hallmark of the impoverished classes. --24.147.86.187 14:41, 9 August 2007 (UTC)

If you consider "smarts" to be "the sum of available information" and "the wisdom to make use of that information", then we are much smarter than we were 5,000 years ago. There is far more information available. Most people are taught to make use of that information through public education. -- Kainaw^(what?) 04:01, 9 August 2007 (UTC)

Kainaw already made one of the points I wanted to make. But on the evolutionary side - 5000 years is a few hundred generations. Provided the environmental pressure is strong enough, that seems enough for a marked evolutionary effect. In the USSR, they bred wild foxes, which are very 'shy' (or what should I call that?), into tame foxes that actually sought out human companionship, in about ten generations (or thereabouts, can't remember to precisely). Now that's a behavioural change, so to do with the brain also. I don't know what strong environmental pressure there could have been for a considerable change in intelligence, but as 58 suggested, women are a force to be reckoned with. :) DirkvdM 06:43, 9 August 2007 (UTC)

I'd definitely agree that 5000 years should be enough for an evolutionary change of this kind. But for this kind to have happened predominantly in these last 5000 years as opposed to the last 100,000 years of homo sapiens evolution the strength of the evolutionary pressure must have become stronger. In other words: Did it require more intelligence do survive and have offspring in the bronze and iron age than in the stone age? I would doubt that; technology makes live easier, after all. On the other hand, the proper use of technology in order to aquire status needed to impress the girls (see sexual selection) requires skill. But this is not a scientific way of thinking of this: The questioner asked the proper question, namely not whether is is plausible but rather whether we have evidence.

The only way to answer this seems to me to look at the life style of stone age hunterer-gatheres and early farmers and ask: Should we be impressed by the clevernessof these people? Maybe we should. After all, it is easier to buy tools than to make them yourself. With the advent of professions and division of labour things became somewhat easier than before, when everybody had to know everything to survive and prosper. And one side-thought: With modern social welfare, you no longer need to be intelligent to avoid starving, and you can even have kids. So, it requires only a little bit of cynicism to say that progress and a welfare society reduces evolutionary pressure on mankind. Simon A. 08:13, 9 August 2007 (UTC)

The difficulty is in separating out the effects of knowledge from intelligence. Sure, we know that we could start a fire by spinning a stick with a bow - but could we have figured that out ourselves if we hadn't been told? Someone in the dim and distant past worked that out for herself/himself - that required intelligence - we only know how to do it because the knowledge that was passed on to us by someone else. I very much doubt that any of us could figure out how to light a fire without the benefit of the knowledge and tools that were passed down to us. Very few modern people actually invent anything - most of us just do what we've been taught - using knowledge gained by others. That was probably true of early humans too - but at least some of them had to invent ways to start fires, to figure out how to smack rocks together to make a sharp edge for a tool, that mud could be heated in an oven to make pottery, that if you heat certain rocks to an insanely high temperature, that you get metal coming out of them. I'm not sure many of us could do that. I'm pretty sure they had similar intelligence to us. SteveBaker 14:12, 9 August 2007 (UTC)

Yes, in the circular sense that: Intelligence tests are designed to measure intelligence; and the performance of people on intelligence tests continues to climb. That's probably evidence against intelligence being a real, basic, entity more than anything else, though. Gzuckier 17:09, 9 August 2007 (UTC)

Avoiding decompression

Would holding the breathe during airplane decompression help in putting the mask first on someone and then on myself? Thanks.

I'm not sure. I think you should actually do the opposite. You should read Decompression sickness. --Mdwyer 20:53, 8 August 2007 (UTC)

No! You definitely have to put the mask on yourself first! If you pass out before you've got it on, you won't be of any help to your nearest & dearest. In any case, holding your breath is going to be awfully difficult if the plane decompresses while you're holding it! If you hold your breath AFTER the plane decompresses then there isn't enough air in your lungs anyway. It's also not just about breathing - you'll be getting all sorts of other problems like extreme pain from nitrogen bubbles forming in your body (like "the bends" that divers get when they come up too fast). The best you can hope to do is to get the mask on yourself - then help the others. There is a reason they tell you this at the start of every single flight! SteveBaker 22:02, 8 August 2007 (UTC)

Even if there is decompression if you're reasonably fit you should still retain consciousness for at least a minute (they did that to a bunch of British soldiers on some TV show and though they became delirious with time they were still conscious for quite a long time). But yea, definitely put your mask on first before trying to help others. --antilived^{T | C | G} 06:33, 9 August 2007 (UTC)

Yes it would help, but it is still no sensible thing to do. The rationale behind the advice to put on your mask first is simple: The child next to you can easily hold its breath long enough for you to pull down one mask, put it on, pull down the other mask and help the child. After all, if the child gets dizzy while waiting not much harm will happen because all it has to do it wait. If, however, you get dizzy because you did it the other way round, you might fail to manage to to you job of putting on both masks. Simon A. 08:18, 9 August 2007 (UTC)

Similarly, if you ever find yourself in space without a suit, do not hold your breath, because your lungs will rupture. SGGH ^speak! 12:17, 9 August 2007 (UTC)

I very much doubt you could hold back that much pressure by holding your breath - the air would force it's way out of your mouth and nose long before your lungs would rupture. SteveBaker 14:02, 9 August 2007 (UTC)

If skin divers can hold their breath at a depth where the outside overpressure exceeds 1 atmosphere, why can't a human hold the air in his lungs when the pressure is only about 1 atmosphere higher than that of the environment? --64.236.170.228 15:46, 9 August 2007 (UTC)

In short, because holding something out (the skin diving example) and holding something in are entirely different matters with different forces at play. — Lomn 15:49, 9 August 2007 (UTC)

A skin diver could never survive a 1 atm pressure difference between the inside and outside of their body! Instead, the diver's body is pressurized to match his surroundings. Your body has no problem being uniformly squeezed by a few atm. If you're in vacuum and don't hold your breath, you can even survive being depressurized for a while. The thing you can't survive is a pressure difference between inside and outside. That's what happens if you hold your breath in partial vacuum. I don't know whether you would actually be able to hold your breath well enough to cause damage, though. --Reuben 16:59, 9 August 2007 (UTC)

Have a look at this answer from an old NASA FAQ: Apparently, your lungs won't get damaged if you let the air escape normally by exhaling. Of course, you get unconcious quickly anyway, but nothing dramatical happens; The scene at the end of Total Recall is of course totally exaggerated. Simon A. 18:36, 9 August 2007 (UTC)

What about the scene from 2001? SteveBaker 19:41, 9 August 2007 (UTC)

Thinking again about it, the article is wrong on one count: You cannot hold your breath unless you pinch your nose closed. The air will simply go out through the nose, which is why subjects experiencing exposure to vaccum lose conciousness within seconds. The article linked to at the end of the NASA FAQ entry is very informative: Geoffrey A. Landis (NASA Glenn Research Center): Human Exposure to Vacuum Simon A. 18:44, 9 August 2007 (UTC)

That's a useful document for answering the OP. It says that at 45,000 feet (35,000 feet would be a more a reasonable altitude for an airliner) - you have 15 to 20 seconds of useful consciousness - and you'll die in four minutes - but that you'll recover if you get oxygen within 2 minutes. So when the 'bad thing' happens - you won't be able to hold your breath - and if you try to put your kid's mask on first, you'll save him/her - but then you'll collapse before you can help yourself - and unless your kid can get your mask on (unlikely) - you'll die. If you put your mask on first then the kid will go unconscious - but you'll have a good minute and a half to get the mask on him/her before there is any risk - getting the mask on an unconscious kid will be a lot easier than on a screaming panicked one. So even if you have several kids - they are safe providing you do as the airline tells you. SteveBaker

Our artical on 2001 one says "In the airlock scene, Bowman is seen holding his breath before being ejected from the pod craft. Before exposure to a vacuum, NASA states, the person must exhale, because holding in the breath would rupture the lungs." Should this be changed or not? --S.dedalus 00:18, 10 August 2007 (UTC)

Yeah - I think so. SteveBaker 02:44, 10 August 2007 (UTC)

No, that is correct. SGGH ^speak! 22:13, 14 August 2007 (UTC)

No. How do you hold your breath? Typically by tightening your breast muscles to keep your lung in its current shape. You do not close your nose. So, if Bowman tried to hold his breath the way he is used to do it he would have been surprised to notice that it does not work. Lacking compensating pressure from outside, the air would simply go out through his nose (provided the pressure falls that suddenly to zero -- as it did in the described NASA accident but as won't happen in case of a punctured airliner cabin). If, on the other hand, he anticipated this effect and pinches his nose to close it, the vacuoles of his lung might in fact burst. Simon A. 07:52, 10 August 2007 (UTC)

Decompression at altitude is similiar to what happens to divers when they get the bends (reducing pressure has dissolved nitrogen coming out the blood as gas). It's your blood that outgasses the oxygen because of the rapid pressure change. This can happen very rapidly. Much more rapibly than you can simulate by holding your breath at sea level. This is one of the considerations for the ceiling maximums for airplanes and is the reason pressurized space suits are needed above 60,000 ft. You must breath purer oxygen at altitude just to keep your oxygen up. A decompression at 40,000 feet can lead to unconciousness in seconds without oxygen. Your blood simply can't keep enough dissolved oxygen without the pressure on your entire body so holding your breath won't help. --Tbeatty 08:14, 10 August 2007 (UTC)

The page Armstrong Limit seems to address this topic somewhat.. Pfly 03:41, 12 August 2007 (UTC)

Male dogs

Why do male puppies squat to pee while adult male dogs lift their legs? Is it a balance issue due to puppies not being as sure on their feet or is it a marking their territory issue that arises as the dog matures? Dismas|^(talk) 20:45, 8 August 2007 (UTC)

My opinion is territory marking. [6]--SpectrumAnalyser 21:33, 8 August 2007 (UTC)

I agree. The adult male needs to get his pee up high enough for the wind to catch the wet patch and blow the smell around. Hence the reason they like trees and lampposts - they provide a place that's above ground level. Peeing on the ground leaves it in the relatively still air that's trapped by the grass and other vegetation. Juveniles need to mask their scent - not advertise it - because they don't want to be seen to be attempting a terratorial take-over so they squat and pee on the ground as inconspicuously as possible. SteveBaker 21:56, 8 August 2007 (UTC)

But wouldn't that mean that the bitches would sit down to pee? Human ones do. Or do they just want to show the male dogs that anything they can do, the bitches can do better? Myles325a 05:39, 9 August 2007 (UTC)

Bitches do squat to pee. Though sometimes, if you keep a bitch among male dogs, she may occasionally mimic them and kind of lift her leg. Rockpocket 07:04, 9 August 2007 (UTC)

Just a thought

Just a thought prompted by a question on ejaculation. Is it possible for a man who never masturbates to orgasm to have an ejaculation due to prostate stimulation caused by defecation. This is a serious question. Please answer seriously--SpectrumAnalyser 22:31, 8 August 2007 (UTC)

Hi Light current. I don't really believe this is much of a serious question, personally. Friday (talk) 22:35, 8 August 2007 (UTC)

The question is serious and relates to a question about the legality of ejaculation in public (on the Misc page) that i answered. Please look there before doubting my sincerity. And what is a light current?--SpectrumAnalyser 22:40, 8 August 2007 (UTC)

Pls refer here [7]

Ahhh...Let me get this straight. You blew your wad in the cinema, and your excuse is that your prostrate was...what was that bit again? myles325a

See prostate massage. If your feces are massaging your prostate (as described in the article), then it is possible. However, feces have more of a tendency to simply exit the body without hanging around to massage anything on the way out. -- Kainaw^(what?) 03:58, 9 August 2007 (UTC)

Magpie nests

Is it true that most of the really old magpie nests are filled with stolen gold, silver and gemstones? --81.77.59.67 22:44, 8 August 2007 (UTC)

Possibly [8]--SpectrumAnalyser 23:19, 8 August 2007 (UTC)

You'd probably find more pieces of tinfoil, broken glass, pretty rocks, snail shells and foils from the top of fag packets than actual booty, though a magpie *did* once steal my grandma's gold wedding ring through an open window, never to be seen again. --Kurt Shaped Box 11:58, 9 August 2007 (UTC)

Are you sure it wasn't a seagull? 151.152.101.44 17:34, 9 August 2007 (UTC)

I saw on a documentary that some species of birds make petal-lined nests/homes to attract the females. Some of the footage was incredible, the birds had made the places amazing. As for magpies I suspect it is a similar desire and actually it is just anything shiny rather than a craving for the gemstones/precious metals that we as society have decided are more impressive than, say, milk-bottle tops ny156uk 22:53, 9 August 2007 (UTC)

Possibly bowerbirds? Some of them typically go for blue (just about anything blue, pegs being favourite), but other species may prefer something more multicoloured. Confusing Manifestation 03:56, 10 August 2007 (UTC)

Space Shuttle tracking

Hi. Does anyone know a website (free, no download required, no registration required), where you enter the town you live in, and it gives you a list of times when you can view the shuttle, where in the sky it is, along with apparent magnitudes? Heavens-above does not yet have the data, Nasa's Human Spacefight website does almost exactly what I asked for but does not give me an apparent magnitude. Also, an actual table of times and brightnesses and alt-az location would be more preferable than a java applet. Thanks. ~AH1^(TCU) 23:26, 8 August 2007 (UTC)

I use a program called Orbitron, I know it does sighting opportunities, but I'm unsure of whether it will do exactly what you want, but give it a try. anonymous6494 07:04, 9 August 2007 (UTC)

Hi. Well, actually, Heavens-above now has info on STS 118 sighting opportunties. Thanks anyway. ~AH1^(TCU) 22:10, 9 August 2007 (UTC)