Wikipedia:Reference desk/Archives/Science/2006 September 26

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I TOLD YOU NOT TO EATFile:NEVER EAT WHEN DOING THISJUST DONT

dont eat while doing this == Gasoline and Fire ==#REDIRECT remember dont eat

As a kid, my friend's dad owned a gas station. He used to work there pumping gas after school and during the summer. Like me, he's a really curious guy.

One day when the gasoline tankers came to refill the station's wells, he asked the trucker who was driving the tanker if he could climb up and see how it was done. It's basic physics, that if you want the hose attached to the bottom of the tanker to release gas into the well, you've got to provide a means for air to replace the gas that's flowing out. Otherwise you'll have a vacuum and the gas just won't flow out of the hose into the wells. So at the top of the tanker there's a "cap" that has to be opened to allow air in to replace the gasoline that's leaving the tank, and basically to allow the gasoline to flow. It's simple physics (I hope I'm describing the whole thing well enough).

Anyway, the hose to the well was clamped shut. My friend climbed up with the trucker to open the cap on top. But he noticed that as the trucker was opening the cap, he had a lit cigarette dangling from his mouth. "Isn't that REALLY dangerous? To have a lit cigarette dangling from your mouth that could easily just slip out and fall into this enormous tank of gasoline?" he asked. "Nah" said the trucker. "It's not dangerous at all". "Watch", he said. He lit a wooden match, and actually threw it into the tanker filled with gasoline. My friend freaked out watching his life race before his eyes. Yet, the match fell into the tanker filled with gasoline, and as it hit the gasoline, it simply went out and just floated there.

My friend had his whole theory of why the gasoline didn't immediately catch fire and create an enormous explosion. But his theory made absolutely no sense to me. My theory was simple: Oxygen. There just wasn't enough oxygen in the tank allow any fire to develop. I'm just wondering how the rest of you would explain how a tanker filled with gasoline wouldn't catch fire and explode even if one were to throw a lit match into it. Thanks! Loomis 00:27, 26 September 2006 (UTC)

I think your explanation is completely correct. However, once some gasoline has been drained and air was entered the tank to replace it, it obviously is a different story... A tanker HALF filled with gasoline very likely has air in it. I think the trucker was too cavalier. Fumes escaping the tank are mixing... --GangofOne 01:07, 26 September 2006 (UTC)

There are other reasons why the gasoline didn't explode. Contrary to popular belief, gasoline is not explosive. A pool of gasoline will burn heartily, but it won't explode the way nitroglycerin will. Your car burns gasoline vapor mixed with air, which is much more dangerous.

GangofOne rightly points out that the fumes in the tank were mixing with the air, but they probably weren't mixing very quickly. Gasoline is very heavy, so it would sit pretty quietly in the tank. Consider how long it takes odors to propagate. Also consider the way that when two slow-moving rivers merge, their water can stay unmixed for several kilometers, e.g. the Amazon River and the Rio Negro, or the Mississippi River and the Ohio. --Smack (talk) 03:39, 26 September 2006 (UTC)

An Explosimeter is a device used to check confined spaces for the presence of, say, methane, which is odorless. If there is too little methane to explode, then the atmosphere is below the Lower Explosive Limit. Just above that percentage of the comustible gas, the mixture will explode if there is the smallest spark. At a high level of the gas the Upper Explosive Limit is reached, and above that the mixture is too rich to explode. Edison 04:34, 26 September 2006 (UTC)

But a match thrown into a vat of gasoline would necessarily have to pass through a region where the explosion fraction exists? no? the fraction at the surface of the liquid is surely too rich while the fraction at the vent is probably too lean but in between, somewhere exists the correct ratio. It is more difficult to explain why there was no explosion than I initially thought. Perhaps the match simply went out (wind) before it hit the tank, I doubt a glowing (but not burning) match would ignite the vapors. --Deglr6328 07:34, 26 September 2006 (UTC)

Yea, that driver is way too careless. Whether you get ignition probably depends on many factors like how full the tank is, the wind, humidity and temperature, etc. I would fire a gasoline truck driver who did anything as foolish as that. Also, somebody is going to get a burnt match in their gas tank, aren't they ? StuRat 09:31, 26 September 2006 (UTC)

In movies, of course, any car full of bad guys that gets into even a minor accident explodes into a giant fireball (cars full of good guys can fall down a huge cliff without any serious injuries resulting). In reality, most accidents, even serious ones, don't result in a fire. In those that do, it's typically a small fire, but can still be deadly, if the people inside the car can't get out. StuRat 09:31, 26 September 2006 (UTC)

The whole time I spent reading this I thought: how does he plan to get the match back? I call BS on this story only because no legitimate refilling operator would toss a match into a tanker and let it get pumped into the gas station. Also, had anyone considered it might be diesel he was filling? (making it much much less volatile at normal temps)... I thought of something else... was your friend standing atop the tanker or off to the side? It makes sense that if there is a hatch on top simply to allow the tank to breathe that it wouldn't be an open hole to which objects could easily fall... I postulate that there was a screen or other blocking device that stopped the match from going anywhere near the actual fuel. --Jmeden2000 13:49, 26 September 2006 (UTC)

The station and probably the tanker have filters in the gas lines to keep out this sort of thing. A filter at the top of the tank would actually be more dangerous as it would keep the flame in a zone more likely to reach an explosive mixture. Rmhermen 17:08, 26 September 2006 (UTC)

This seems to verify the plausibility of the anecdote, even though it doesn't provide a reason why. 80.169.64.22 16:09, 26 September 2006 (UTC)

It's possible the whole story could be BS, the guy's not really a close friend, but I don't see why even a pathological liar would come up with such a bizarre lie for absolutely no reason. Liars generally have some sort of incentive to make things up...anyway, that's all beside the point. The reason the whole thing came up is because I told him a story of my own. I'm embarrassed to say that I'm an on and off smoker...I've quit many times for rather considerable amounts of time, but during stressful times I tend to go back. But I know I'll be able to quit for good one day...but that's also beside the point.

I had two reasons for bringing up the whole issue with this friend: One is that our neighbourhood mechanic happens to be a chain-smoker. At his garage (which is also a gas station) he doesn't even use an ashtray, but simply tosses his lit cigarette butts wherever he wants. The whole thing seems rather dangerous to me. In fact, it's actually a law here where I live that while you can buy cigarettes at a gas station, they're not allowed to provide matches...they're only allowed to sell you lighters. The reason seems pretty obvious to me. For safety reasons, they just don't want people lighting matches at gas stations and tossing them on the ground.

The other reason is the fact that whenever I'm smoking outdoors, I have the habit of tossing my lit cigarette butt into a sewer rather than on the street. However on at least a couple of occasions I happened to be walking near a gas station, and seeing a bunch of sewer-like holes in the ground I almost actually threw a butt into one. Of course I managed to come to my senses and realize that it was no sewer I was about to throw the butt into, but rather a gasoline well! Thankfully I never actually did anything as (what I thought) would be so extremely dangerous as to throw a lit cigarette butt into a gasoline well. So I told this to the friend and that's when he told me the whole story about the tanker at his dad's gas station.

But I'm still wondering, surely I'm not the only person in the world that could mistakenly throw a cigarette butt into a gasoline well. Yet the caps on the wells aren't completely sealed. They tend to have these little holes in them. How is it possible that there seem to be all these explosions just waiting to happen? You'd think the wells would at least be adequately sealed, and if the reason they're not is because of the old physics necessity of requiring air to replace the gasoline as in the gasoline tanker, you'd think that they'd at least have some sort of piping that would allow the required air to come in from somewhere less dangerous such as, perhaps, the roof of the gas station. Any comments would be appreciated. Thanks again. Loomis 00:53, 27 September 2006 (UTC)

You haven't seen them? Look for the (usually white) row of ~2 inch pipes sticking out of the ground nearby next time you go. --Deglr6328 10:04, 27 September 2006 (UTC)

Kids! Don't try this at home! Mattopaedia 11:55, 28 September 2006 (UTC)

Down-grading of serotonin receptors-prevention

As we know, serotonin bombardment may cause its receptors to hide for a while out of reach of the monoamines- is there any way to prevent this? Thanks. -R.

I don't think we know of a way at this time. The receptors are drawn back into the cell because of their reaction with the serotonin. The more serotonin, the less receptors stay on the surface of the synapse. There might be a way to disable to inhibit this mechanism, but we're not sure exactly how it works, so we don't know how to do so. But taking ecstasy while this mechanism was disabled would likely have very harmful effects. Downgrading of receptors protects the cell from excitotoxicity, among other things. --Crazy Wolf 01:33, 26 September 2006 (UTC)

Harmful? Yes, it would kill you. There are compounds that modulate the action of serotonin, and you can find out about them if you want, but I'm not going to lay it all out. I hope you're not one of these, but surely some idiots would love to boost their E-hit in spite of the mortality risk. I'd question the appropriateness of publishing the how-to in wikipedia. Mattopaedia 04:34, 30 September 2006 (UTC)

Palpitations

OK Ive just been told by a doctor that my heart palpitations (missing beats) are nothing to worry about. But i am worried. How many people get heart palpitations and whats the typical ratio of missed beats?--Light current 02:34, 26 September 2006 (UTC)

A lot of people get them. My grandfather has had them most of his life; he will be turning 90 in a few weeks. My father has them every once in a while as well. - R_Lee_E (talk, contribs) 02:44, 26 September 2006 (UTC)

Yeah but Im not as old as your father. How old is he?--Light current 02:59, 26 September 2006 (UTC)

He is 48. My point is that you do not have to worry about it. That is not to say that you can continue to abuse your heart (not assuming that you do). It is good that you spoke to a doctor about this, because you wouldn't want to confuse the palpitations with a more serious condition. - R_Lee_E (talk, contribs) 03:01, 26 September 2006 (UTC)

Exactly! 8-)--Light current 03:03, 26 September 2006 (UTC)

It's probably nothing to worry about, but you should probably see a cardiologist and get a thorough EKG. --Smack (talk) 03:27, 26 September 2006 (UTC)

A doctor said one could have lots of prematore ventricular fibs. He said that stress, lack of sleep, alcohol, and caffeine could be factors which increase the rate. Other anecdotal info is that atrial fibrilations are more serious and may cause strokes. As always, get your medical advice from doctors and not random people on the internet.Maybe see a cardiologist, get an EKG and/or stress test and put your fears to rest.Edison 05:03, 27 September 2006 (UTC)

My heart (nearly) stood still (Rodgers & Hart)

Progress statement #1

Im ok today (no palps). But Im going to try to get an appointment to see the doctor (ratther than just talk with one)--Light current 03:53, 26 September 2006 (UTC)

Obviously you should see a doctor, have an EKG, and probably undergo a Holter monitor. They may have you undergo an echocardiogram to make sure that you have a structurally normal heart. And then, depending on the results, they'll be able to tell you if everything truly is okay because obviously some sources of palpitations can be deadly. As far as arrhythmias go, I've been in and out of ventricular bigeminy for the last 48 hours. Maybe an increased risk for sudden cardiac death, but even with such a high number of premature ventricular beats the data is not clear that there is any increased risk for mortality. InvictaHOG 04:17, 26 September 2006 (UTC)

Have you seen a doctor? Or are you a heart specialist yourself?--Light current 01:21, 27 September 2006 (UTC)

How much coffee do you drink? JackofOz 06:44, 26 September 2006 (UTC)

I don't drink any coffee or have exposures to any stimulants. Haven't had caffeine in years. InvictaHOG 07:49, 26 September 2006 (UTC)

Thanks. My question was actually directed at Light current. JackofOz 08:13, 26 September 2006 (UTC)

About 2 cups per day (decaf)--Light current 22:45, 26 September 2006 (UTC)

Progress statement #2

Since my last statement, I got to see one of the GPs in my practice this morning. She checked BP, heart rate only and, as they seemed fairly normal, said she would like to run some tests:

• blood test for thyroxin etc
• ECG for heart function

I think the doctor did say that if the ECG proved ok, I might be required to undergo a 24 hr ECG monitoring.

Got blood sample taken (almost) immediately at GP surgery. Now this nurse is an excellent specialist phlebotomist - a real artist- just one small prick and its in! Hardly hurts at all! (Mind you she's been doing it for years). Then I proceeded down to the local hospital for ECG (EKG). No waiting time! ECG suite nurse wired me up and finally got a print out but the nurse was not happy and said she would have to get an ER doctor to look at it (they didnt have any doctors in the ECG Dept!!). When she returned, she said I would have to go to A&E (ER) as it looked suspicious and they wanted to check me again.

This time I got a real pro 'ER' Sister (Team leader) wiring me up to a more sophisticated machine that also took BP, ECG and respiration rate (and probably measured my inside leg at the same time for all I know!) etc while she asked a lot of questions about name, address, next of kin, pain, coffee, unusual activity etc. It got me a bit worried!

She then left me to stew for a while. The machine beeped a lot. It started to get on my nerves. I tried to relax. The BP cuff inflated at intervals of around 10 mins. I tried to crane my neck around withoud moving my body to much and saw that the BP was OK and pulse rate about 75. I thought 'It cant be too serious with figures like that can it?'

When she came back one time she slipped an identity bracelet onto my wrist. I thought 'oh no: I'm staying here'. Then someone eles came round and asked if I wanted any lunch. I said 'no, I wont be staying that long! She said ' Youll be here for quite a while, epecially if they have drawn blood!' Shit! I thought-- I got to go to work and I'm parked in a 'limited time' parking bay. 'No, its ok' I said , I'll have a lemon squash. About 30 mins later a youngish woman dressed in a blue top and trouser outfit came and said 'Hello, My name's Lola, I'm the doctor what is your trouble?' I expalined for the umpteenth time then she said 'I think youre ok but Ill just have listen to your chest and then weel take some blood!. I said 'Is this going to take long? i really could do with a c***. 'Well is it urgent?' she retorted. 'Not if youre quick' I replied. She seemed satisfied with what she heard through the listening gear and said 'OK when you return, we'll get some blood'. I asked ' Why do they always have trouble taking my ECG?' She said I was one of the group of people to have an 'inverted P wave'? which can indicate a heart attack in people with normal P waves. So how do they know who normanny has a n inverted P wave and who has had a heart attack? Anyway, finally, she said that the trace was the same as I'd had done about 6 months ago when I went for ODing on my prescribed medication.

When I returned from the toilet, there was a strange looking young male in my cubicle sort of grinning at me. I said 'No its OK Ive just seen the Doctor!' 'No', he said 'Mr Current'? I have to take some blood from you'. 'Ok' said I as I climbed back onto the couch. He looked at both my arms and seemed to expressed a preference for my right (my left having already been puncured once). He spent quite some time prodding and poking the barely visible veins on the inside elbow. He rubbed and fingered and rubbed again alternating between two spots about an inch apart. Finally, he pronounced 'I think we'll have a try at this one first (indicating a vein near to the indide of the elbow), then, if it doesnt work, well try the other place'. If it doesnt work??? What the hell did he mean by that? 'Here we go' he said 'Small scratch'.

Waaaahhhh!!!! Nearly jumped about 3 ft off the bed! WTF (loud expleteives deleted). 'WTF are you doing? Take it easy! Stop bending the damn needle!' Attachment of vial produces no blood. 'Ah that one didnt work' he says casually. 'Now we try the other place!' I said 'yeah well this one better not hurt as much as the last one .. He said 'Oh yeah, it hurt ther because there is a tendon just there! I really was thinking of telling him to piss off and get someone who knew what (s)he was doing but in the end I decided to let him have one more try. Luckily, this didnt hurt much and was sucessfull in bleeding out.

He took three vials I believe. I said 'Look mate/buddy, dont lose those whatever you do! He was about to go with the vials with no markings as to their producer, when he halted and said 'Oh BTW, what is your name again please?'. I said 'Current'. 'Oh', he said 'we have a river boat company by that name where I come from!' 'Where?' I asked.. 'Bolivia!' was the reply. Yeah, and I always thought it was safer over here than in Bolivia! At least two long boring hours wait for path lab results. Then finally, Sister says casually: 'We've got the results. They're OK. You can go home now'. I exit premises at high velocity! 8-) TFFT! NB All names have been changed to protect the innocent/guity --Light current 22:43, 26 September 2006 (UTC)

Flu vaccines

In immunology we were taught that a vaccine is essentially an attenuated version of the virus that the body can fight off and create virus specific antibodies for. I am under the impression that the Flu vaccine is updated every summer with last seasons mutation of the Flu virus. So every vaccine will consist of a collection of viruses from many seasons that your body will fight off and you gain immunity to the past versions of the Flu virus. My questions are

1) The Flu virus mutates very easily, so does that means we aren’t necessarily immune to the present season’s mutation of the flu virus. Does that mean we can still catch the Flu virus even after taking a vaccine?

2) Flu season is only in the winter months. Is there a reason why the Flu virus isn’t active during the warmer summer months? Does this have to do with the stress that cold weather places on our bodies or is the Flu virus temperature sensitive? If the latter is true, does that mean that warm tropical environments are Flu –free regions?

1. Yes, you can get the flu even with a vaccine. First, no vaccine is 100% effective. Second, vaccines take a long time to develop. The pharmaceutical companies take a guess at which strains will become widespread, several months in advance, because they need that much time. And, of course, they make mistakes. --Smack (talk) 03:29, 26 September 2006 (UTC)

Each vaccine contains three influenza viruses-one A (H1N1) virus, one A (H3N2) virus, and one B virus. The specific viruses to be included each year are decided by a panel, based on information about current viral strains and on how well antibodies made to the current vaccine react to the circulating virus and new flu viruses. For 2006/7, the strains will cover A/New Caledonia/20/1999 (H1N1)-like, A/Wisconsin/67/2005 (H3N2)-like, and B/Malaysia/2506/2004-like antigens). So it is not simply a matter of "last season's mutation". The injectable flu vaccine is inactivated (killed), not attenuated. Thus one cannot contract influenza from the injectable flu vaccine. The inhaled (nasal) vaccine, on the other hand, is attenuated. On average, one or two strains are changed each year.

1) You certainly can catch the flu virus after taking a vaccine, whether the strain wasn't included or not.

2) Much of the reason for having a flu "season" in temperate zone is thought to relate to the fact that people spend more time together indoors in close quarters during that time. Differences in transmission at different temperatures may also be involved, but most of the variation is thought to be due to the larger number of people exposed to an infected individual in the winter months. - Nunh-huh 03:35, 26 September 2006 (UTC)

thru edit conflict, and so, with an addendum: no, pharmaceutical companies do not make the decisions. The decisions on which strains to include are made on the basis of presentations by an advisory committee of the U.S. Food and Drug Administration (FDA) at a WHO meeting, based on data compiled by the WHO and the CDC. - Nunh-huh 03:35, 26 September 2006 (UTC)

Heart muscle

Normally a skeletal muscle gets fatigue after a forceful contaction but why does the heart muscle do not get fatigue though it works continually?Is there any special reason or structural variance from skeletal muscle that causes heart muscle not to fatigue?

[[Heart muscle]] redirects to Myocardium which links to Cardiac muscle. I had a look, but I couldn't find an answer. Googling tells me that the high number of mitochondria is the key. --Kjoonlee 04:33, 26 September 2006 (UTC)

There are two main parts of muscle fatigue. The first is based on the fact that the neurons that tell your muscles to fire eventually run out of neurotransmitters. The second is that the muscle runs out of oxygen and can't contract for too long without oxygen or lactic acid builds up. Heart muscles can fire so often because they are not activated directly by neurons, they have a lot of mitochondria, and the heart gets first dibs on all the oxygen that is being supplied to the body. There might be other factors, but I don't know them. --Crazy Wolf 05:05, 26 September 2006 (UTC)

Speeding up iron oxidation

Iron oxidation runs many hand warmers. The iron is mixed with water, activated charcoal, a salt, vermiculite, and cellulose. However, this reaction is quite slow. It will heat up the packet to a comfortable temperature and run for several hours.

I was wondering if it is possible to speed up the reaction so that it will heat up quickly to high temperatures(400-500 degrees celsius) for a short period of time(5-10 minutes). What controls the temperature of the reaction? Finally, does this reaction give off any fumes that are harmful to breath?

Also, are there any other chemical combinations that would do what I am looking for?

thank you --Crazy Wolf 05:19, 26 September 2006 (UTC)

what you are after is a thermite reaction. not the classical iron oxide/aluminium thermite reaction, because that burns a bit hot for your purposes. but another mixture will do it. but it will involve open flame. alternatively, decreasing the size of the iron particles should boost the rate, and thus the temperature. or you can change the metal. can i ask what the purpose is? that may help with what temperature you can get away with, and thus what reaction to use. Xcomradex 07:26, 26 September 2006 (UTC)

I am looking into using it to heat up material for inhalation(tobacco, oils, etc.). I can control the heat if it is too hot, but it has to generate at least 400 degree celsius temperatures. Any temperature up to 1000C would be ok. The reaction has to initiate either from contact with air, mixture of the ingredients, or the heat from a butane cigarette lighter. The fumes have to be safe to inhale and not smell offensive, and it can't make smoke. I figured that would rule out thermite reactions. It also either can't leave behind much in the way of ashes or can't be too hot to stay within a fabric container. --Crazy Wolf 08:38, 26 September 2006 (UTC)

Actually, it can leave behind solid residue if it doesn't melt, because I could keep it in a metal mesh cannister. --Crazy Wolf 08:44, 26 September 2006 (UTC)

then i'm guessing an inorganic fuel and inorganic oxidiser? the residues have to be non-toxic, which rules out a lot of organics (produce CN etc) and inorganic nitrates (produce NOx). i'm thinking something like sodium peroxide would be a good oxidant, either with a metal powder (probably a bad idea, lots of heat + non-extingushable flame = lawsuit) or an organic fuel. if you choose a liquid like glycerol, the reaction can be initiated by addition of the liquid glycerol to solid sodium peroxide (a match might be needed, you'd have to test it out). alternatively, an oxidant like potassium permanganate spontaneously ignites glycerol, that might be a good one to try. i can't help thinking electrical control will be easier and safer. and of course the usual rd/sci disclaimer: you try this at your own risk. get the levels of toxic gases checked by a professional lab before you do anything too dangerous. Xcomradex 10:54, 26 September 2006 (UTC)

Thanks for your help, I'll look into some of those and check the safety. --Crazy Wolf 20:00, 26 September 2006 (UTC)

Yeah! Let's sell the 'Porti-Bong' for Wikipedia! Could make lots of money, and serves as a hand-warmer as well!.... --Zeizmic 11:55, 26 September 2006 (UTC)

thats how i read it too Xcomradex 21:43, 26 September 2006 (UTC)

Liver transplant

Alright guys. A follow up and some more questions before I email experts at the end of the week. Well. It is going better. I managed to skillfully manipulate her (that was a hard one) into considering rationally a liver transplant. Only liver transplantation offers an effective cure for the condition by both correcting the recipient phenotype and normalizing the circulating levels of A1AT so the neutrophil elastase can be regulated. She said the option had already been given, and "while it has been presented to me as an option, no acceptable donor will donate." I already thought about it. In a few years, when it is most optimal for both of us, if she doesn't get a donor, I want to. I want it more than anything in the world. If I can't find anybody else that will do the living donor liver transplantation, I will. This is the thing I have most wanted in my life, not only because it is her, but because she is my best friend and fellow human. I hate that people do not expect anything of me because I am 15. My ability and time is not as well spent as it could be, because no body needs anything of me, no body expects anything of me. Although she doesn't want me to think about it, I have been for the last week, and it gives me something more to expect of myself, that she needs. It is my first chance to actually do something big. Of course she was very flattered, but turned me down because "Even the mere hint of someone being hurt by my illness is deplorable, selfish, and I refuse. Curtiously." I replied that it is "Completely absurd to compare me losing something for three months that I can live without, to you losing something forever." To that which: "You're right. It is absurd. And you can't understand right now, but bear with me long enough to let me make you understand, because I want to share that with you horribly. I want you to see that I am happy by the mere thought of your willingness, nay, excitement, to do this. But I don't want you to, I don't want to. Without doubt." Although I will keep into consideration of course, there are other things to do, this is the only option that she would do, possibly. She has given up looking for donors. She's on the lists. Her parents are on the lookout, but no donors, she noted no possibilities. I believe I have given her hope, it is not stressing our relationship very much anymore, and I made her want to tell her parents about it. She said she would, and I think she will. Whatever she says her parents should be interested. Nay? Of course I should wait, because I am not biologically strong enough yet. But the longer we wait the worse her lungs get, which will not go back (without even more medication which may not exist already). I am thinking 17-19. But there are some ifs, and I need your help with a few things. I have forgetten where or if I read it, but I would have to have compatability with her. If I am correct all that has to be is the compatiable ABO blood types, and MHC proteins, but it is better for the patient if she has more alike antibodies. Help here? Research is going on at Northwestern University that looks promising regarding new immunosurpresive drugs that do not have as many of the side effects as the glucocorticoids do.

We are on a lighter tone now, and for both of us it is unacceptable to do what the other wants, however I do sense some budging and hope being produced. I need to crack her. It has been very tough, but with a combination of luck, determination, skill, and courage, I have taken down most of her walls. She has formed walls to make her ok with the ailment, and accept it. However the walls compeletly block the sure light of hope to her, and I am destroying them easily. I have to, before she will have hope, which is necessary for her cure, present and/or future. However there are two that I haven't tried yet, because I couldn't not be for sure.

She says that she does not want to live more than her lifespan. She asked me: "If you had a paper to write with a time limit of one week, how much harder would you work to write that paper than you if you had a year to do it?" I almost agree with her. However I don't. I don't know what to say. Maybe I am wrong and she is right. What do you think? I don't know how to elequently persuade her for this one.

The last one she hasn't told me yet. Help me anyway you can.

I've always thought people use the words "hope" and "you're welcome" far, far more than they should. They are words that are used sparingly when uesd well. I never "hope" I got an A on my algebra test, I never "hope" I get a new video game. I hope she wants to do it almost as much as I do. I hope that my liver would be compatiable with her body. Any treatment that is not a quick cure, she will not do, because she's been through so much already. The blood types. This is a further manifestation of the cruelty of all. Imagine marking a coin on one side, and flipping it. The side you marked is life, the side you did not mark is death. She is fourteen, and both sides should have been marked, but only one was. Thanatopsis. — X [Mac Davis] (SUPERDESK|Help me improve)05:38, 26 September 2006 (UTC)

I agree with Bowlhover from the first part of your discussion; false hope is much, much worse than no hope. And transplants are, in all honesty, generally overrated. This is not saying that they are useless, indeed, far from it. I'm currently a little over three years on the kidney transplant waiting list myself, so I'd like to think I have a little perspective on the matter. Firstly, the matter of compatibility is not a small one; non-related donors have a fairly small chance of being compatible. Secondly, there are other issues at stake. At least where I live, the transplant program will reject anyone with even a slim chance of themselves suffering from organ problems down the road; they are proud of their track record of never having someone donate an organ and then need one themselves later, and rightly so. I had my mother and my uncle both attempt to donate a kidney to me, and they were both rejected for this reason. (As a side note, while I'm never one to preach for or against substance abuse, if you are as serious as you seem, you probably don't want to take up smoking, drinking or drugs -- any liver damage will really reduce your shot at donation.)

Finally, a transplant is not a cure. It's a treatment. Read those two sentences again. Yes, it's a better treatment than most; providing more complete function and great independence, and often lasting years or even decades, but it's still a treatment, and no treatment is permanent. When you get an organ donated to you, you take ridiculous amounts of immunosuppresants; the local cocktail here is Prednisone, Imran, and Cyclosporine. These are big-league, no-shit drugs. Read the side effects -- Prednisone is a notorious mood alterer. Cyclosporine can cause toxicity in both the kidneys and liver. Ironic, dontcha think? Imran is a known carcinogen. You read that right; they give you drugs whose side effects include cancer. From what I've heard, it's a really brutal set of medications -- they give you three in combination so you don't have to take so much of any one. Plus, there's a whole whack of other pills you have to take, like antifungals -- trying to prevent stuff like Oral thrush, which mostly affects babies.

In the end, with the immunosupression and the side effects, it's very common (really closer to inevitable) that eventually a transplant patient comes down with a serious infection, like pneumonia, or cancer (lymph node and skin are popular) or something else where the medical team must eventually make the decision to stop immunosupression to let the body fight the disease back. Which means losing the organ. Organs also often spontaneously reject. I'd be surprised if a young person like your girlfriend (hell, like me) were to get a transplant, live a long life, and not lose the first organ at some point. Like I said, treatment. I'm not even 100% convinced that I'd accept a cadaver donor transplant if/when one came up. I'm still wrestling with the issues.

Honestly, the walls that as you put it "block the sure light of hope" are blocking a dim light, and not even a sure one. What they are providing is to "make her ok with the ailment, and accept it". This is, in many ways, a hell of a service. We all die, most sooner than we would like, and coming to grips with this is one of the best things that has ever happened to me. To be sure, I have some hope, but I also realize that there's a lot of pain on my road. I've had four surgeries in the last four months, for instance, all relating to dialysis. I currently have two catheters hanging out of my abdomen -- one attached to my jugular -- and I'm really hoping I can bathe again by Halloween. I can see where your girlfriend is coming from, at least part of the way. I decided a long time ago that I was never going to ask my friends or family to donate a kidney for me. Two of my closest family members tried, and I'm grateful to them, but they did it on their own. I'm guessing you've never had abdominal surgery. I have, and more minor than liver lobe donation, and it sucks. It hurts like hell, and recovery takes time. That's a lot to ask from someone, it puts a lot of responsibility on the recipient; and I can respect your girlfriends' position that it's too much to accept from someone she cares about. Look, hope's a great thing, but so is peace of mind. I know it seems like life's not fair. Get used to it. You want fair, play Candyland. I was supposed to be in India right now, but an incisional hernia that incarcerated in June put me in the hospital for a week, and forced me to cancel the trip. Cancelling the trip hurt more than the emergency surgery I had; in fact, it was possibly the worst thing about the whole experience. I guess what I'm trying to say is that false hope, or a thin shred of hope can be worse than no hope at all.

Good luck with this; and, of course remember Wikipedia is not a reliable source for medical information. --ByeByeBaby 06:47, 26 September 2006 (UTC)

Thanks for your reply. Are you informed on A1AD? From what I have read, and some other people have told me, a liver transplant is a cure.[[1] updated] [2] I know about the immunosurpression, and it is not all good, but the person can live a fairly normal life, certainly compared to before, and developments will happen, and are happening. How do the side effects compare with the adverse ones she has now exhibited from weekly augmentation therapy? I know we're probably starting to get out of the range of most people here. The cocktails all seem to be the same few three drugs (there's only a few), and at least the same three functions for each. In fact, she's ok with them. Right now, I think that if it weren't me, and it were some dead guy she and her family would do it right away, or when significantly bad things started happening. I'll talk to a few people after this of course. Me needing organs? The liver does grow back. From the journal articles I have read, it looks like there is not much of a case with the live donor's life, or this recipient's life in the first year. Detereoration of success rate over the years is due to immosurpression and the bad condition recipients were in to start with? I know I for sure that I don't know what I'm getting into, if it does have to happen. However, the few months of pain for me do not compare to the pain she has had, and loss of life—it is absurd. Of course life isn't fair, thanks for telling me. Everybody I've told has seemed to say that, as if I didn't already know. I did, but now it is real. I guess we're all in An Open Boat. I decided long ago I would try and make it better for everybody. Ha ha, sounds funny to you, but it is going to happen. This is my first chance—a small job. I can say I am doing close to my best. Only one person and the family and friends. Possibly the parents won't have to see their child die before they do. We'll see how my idea changes with further research. — X [Mac Davis] (SUPERDESK|Help me improve)07:17, 26 September 2006 (UTC)

Well, obviously there are a lot of words on this page. I just want to add a few. The most important one is that, while liver transplantation is a cure for AAT deficiency, it is itself a chronic illness which must be managed. As has been said, it would be out of the ordinary with today's medicines for a liver put in today to last your girlfriend for the rest of her life. It will stop the AAT, but only so far as substituting a different, equally deadly disease. Additionally, in order to donate you not only have to be a perfect match (unlikely, to tell you the truth) but you have to undergo extensive psychiatric examination once you reach the right age. I understand that you see yourself as someone who is raging against the dying of the light, but an equally important part of life is coming to grips with a chronic, life-limiting illness. Obviously, your girlfriend and her family need to explore all of the possibilities. However, you should make sure that you interject your feelings in a respectful and understanding way. Believe me, they most likely know much more about the issue than you do and haven't come to their conclusions without a lot of thought! InvictaHOG 08:07, 26 September 2006 (UTC)

What might be this equally deadly disease substituted by the liver? Management? I realize of course it is most likely that I would not match, but I do want to get her to consider it, so that I can see if we match. If this doesn't work, I'll give up for a little while. I am a raging-against-the-dying-light, Sisyphus kinda guy. At least for myself. I try for other people, but if they want to go, I can figure. But they must consider. After a rational consideration I accept any conclusion. — X [Mac Davis] (SUPERDESK|Help me improve)08:14, 26 September 2006 (UTC)

Liver transplantion - I am trying to make sure you know it is not easy and is not a final solution. You trade one disease for another. Maybe AAT will have a cure before we can make liver transplantation a more manageable disease - maybe there's a lot to consider before an elective transplantation of this nature. InvictaHOG 11:17, 26 September 2006 (UTC)

Of course, and they'll have to consider it. I only want them to consider it now, instead of not considering anything. — X [Mac Davis] (SUPERDESK|Help me improve)15:18, 26 September 2006 (UTC)

Well. I cracked her. And she finally told me. She's O-. That's why no body she knew could donate. And why she's always saying that I couldn't do anything. I can't. No body is ever going to give their liver to somebody they aren't close to. Naturally, everything has worked out against her, and she has gotten the short end of the stick over and over and over again. Have I lost hope? Pretty much. I'm giving up until next year. I'll be watching developments. Thank you for all your help guys. I still wish she was anything else but B or O. — X [Mac Davis] (SUPERDESK|Help me improve)21:27, 26 September 2006 (UTC)

Mac: This may be hard to appreciate, but you must distinguish your generosity in seeking to donate part of your liver to this girl fromthe relationship you have or want to have with her. Place it on the same level as donating to someone you hardly know. There is the danger of feeling like such a gift would cement a relationship between you and her. The sense of obligation from such a donation would almost insure that the obstinacy of the human spirit would make her fall for someone else. If you seek to donate an organ to someone, consider if you would do the same for someone who was the true love of someone else. You would not want someone to have strong feelings for you out of a sense of debt. But you sound like a good and generous person. Edison 05:15, 27 September 2006 (UTC)

I concur with Edison. This is along the same line of reasoning that I've refused to ask friends for a kidney. I reversed the situation, and realized that there were people who I'd donate a kidney to if they asked me, but for whom I'd not volunteer on my own. So I decided it was unfair to put that pressure on other people. But the reverse is also true; by receiving a liver from you, your friend is put in the situation of being in debt to you. I thought of a similar situation last night as I was falling asleep; a few years ago, (I was around 23), my mother and I were talking about finances. I can't remember exactly what we said, but she spontaneously wrote me a cheque for $10,000 as a gift. (My family is solidly middle class.) The gift was ridiculously generous, and just literally too much. I looked at for a few seconds, then tore it up. (And yes, as I later found out, the cheque would have cleared.)

I guess what I'm trying to say is that there's a lot of issues involved here. That there's value in both fighting off death and also accepting death as what makes life valuable; that there's value in generosity, but also implications of that generosity. When you first posted on this topic, you were coming from an extreme on one side of the equation, but it helps to consider both sides. And I think that I just now realized that part of what I was writing about not wanting your friend to get false hope was really aimed at you, as well; you seemed to be so full of hope that you couldn't see the risks and downsides.

Anyways, I'm sorry that your girlfriend is O-, and that the future seems bleak right now. I wish the best for both of you, and I'd like to compliment you on your intensity and generosity of spirit. --ByeByeBaby 06:13, 27 September 2006 (UTC)

I did think about it, if I would do it for somebody I didn't know. I wouldn't in almost every case, but not this one. Even if I didn't know her, the situation is different. You already know what it is, she is 14 and dying from emphysema, and that should not happen. I know that almost no body could really deserve it, but if it was an adult, that would almost be ok. But she's fourteen, and it is not. I will admit that I would not have done anything about it if I didn't know her. After she fufilled the obligation to tell me, I have the obligation to fix it. It isn't just because she is my girlfriend, she is my best friend, and my fellow person. We're 15 years old—I mean, we're not getting married. I don't care if she would "fall for someone else" all I want is for her to live. I thought about the generosity-debt issue. To me she would never be in debt, but to her, of course she would feel indebted. I don't know. But she would not have to die so young, and her parents wouldn't have to see her die. Like I said, I think if it were some dead guy she would do it right away. But it was me, she was very touched, and she turned me down. I am not giving up however! She's not dying on my watch. Unless she really wants to. Which would border on suicide. I don't know, it gets too confusing. I will start my nanobiotechnology higher education next year, and I wonder what will happen. I could probably have the oportunity to try and reap vengence upon this, or another illness like this. Of course, just as a figure of speech. Really I would be doing it so no body else would have to worry about it or suffer again as much as she and those today have. We'll see. To say "however" again, I would rather have less bandages, and more real fixes, but I am no geneticist, or am the slightest bit interested in it, so couldn't work on this problem. — X [Mac Davis] (SUPERDESK|Help me improve)06:41, 27 September 2006 (UTC)

Silver cars are safer

A couple of years ago, the University of Auckland (NZ) conducted a study correlating accident frequency and colors of cars. Here's one link desribing it. According to the study, silver cars are quite a bit safer than white, yellow, grey, red, and blue cars and much safer than green, black, and especially brown cars. Discounting other factors (silver cars might be more expensive, people who prefer silver cars might be safer drivers, certain 'unsafe' models might not be available in silver etc.), and keeping all things equal, what do you think is the reason for this? Is it the reflectivity which makes them more visible than white cars? Moreover, assuming this study was published in several journals, does anyone know whether the preferences in chosing a car's color have shifted toward silver during the past couple of years?---Sluzzelin 07:31, 26 September 2006 (UTC)

I think to have a car just plain silver that can denote it not being expensive. My conjecture is that price can roughly correlate to the saftey of the car. — X [Mac Davis] (SUPERDESK|Help me improve)07:54, 26 September 2006 (UTC)

Yes, that's a good point, Mac. But some of the reports I saw on the studies claimed that price and economic status had been taken into account (also mileage, age of the car etc). That's why I would like to know whether, ceteris paribus, anyone knew of a plausible physical/perceptory explanation for this correlation.---Sluzzelin 08:22, 26 September 2006 (UTC)

I would say highly reflective shiny vehicles might make accidents involving those cars less common, because they are more visible, but also might cause other accidents involving unrelated vehicles, because people blinded by the reflected sunlight run into something else. Cars should not be allowed to be shiny, as this is an obvious accident risk, as well as causing eye damage. Flat optic orange (sometimes used on golf balls) is both easy to see and not blinding, so that's the color I would recommend. Also, if we could make them glow in the dark, that would be even better. StuRat 09:01, 26 September 2006 (UTC)

There is another angle on this one, is that persons with a certain safe personality will choose grey and silver colours for there new car, whereas other personalities prefer a more agressive colour like red. The latter wil create more accidents making the former safer. This info comes from the insurance companies, as a result the carproducers pick the colors for the targeted group.Mion 09:09, 26 September 2006 (UTC)

Yes, I believe two-seaters are much more expensive to insure, for just this reason. There is nothing inherently unsafe about the cars, it's the drivers who choose them that are unsafe. StuRat 10:02, 26 September 2006 (UTC)

Or is it that the number of silver cars is less ? If we start producing more silver cars, then their involvement in accidents can go up - Wikicheng 09:46, 26 September 2006 (UTC)

Not as a proportion of the number of silver cars, which is how it would be measured. StuRat 10:02, 26 September 2006 (UTC)

Companies tend to lease silver or grey cars for the sales department, because the color is neutral, meaning after 3 years the market is flooded with the grey and siver versions, resulting in the cheaper prices for these color cars. Mion 15:36, 26 September 2006 (UTC)

I saw two similar studies on traffic tickets. Red cars are most likely to get traffic tickets. White/Silver cars are least likely. The study said that it is possible police tend to notice red cars more - which is a bit silly. They sit there eating donuts and drinking coffee until the radar gun goes BEEP BEEP. Then, they chase the car that just went by - regardless of color. So, in my opinion, this shows that people in red cars are more likely to speed - which would lead to them being more likely to have an accident. --Kainaw ^(talk) 13:46, 26 September 2006 (UTC)

For what it's worth, I have always considered red, yellow, and teal cars "safer" and black grey and brown cars "less safe". I have done no research, but I can definitely say that I have had many close calls with grey and silver cars in low-visibility situations: they just blend in with the environment better. From a few interviews with owners of yellow cars, however, I have heard that bees tend to be more interested in yellow, and thus possibly more likely to fly in your window (though I have only heard this with Audis, perhaps there is a UV dye in the paint). (I was planning on buying a yellow car a while ago and that's why I interviewed in the first place, I ended up with silver though (it was cheaper)). I feel that it is more important to be conspicuous than to avoid blinding other drivers (not that that wouldn't be bad, it's just that I don't think it happens much, it's never happened to me at least). I'll add the note that here in the US daylight running lamps, though common, are not mandatory, I know that this is not the case in Canada and suspect that many other countries have come to their wits as well.Tuckerekcut 15:28, 26 September 2006 (UTC)

Thank you for your replies. I originally assumed significant human factors could be ruled out, and that the correlation might have to do with the fact that a silver car's high reflectivity also might make its motion more visible. Since cars involved in accidents are usually moving, I thought they might be more noticeable with light patterns flashing across their surface. I wasn't able to directly access the study, but some of your entries make me think that, perhaps, it is very difficult to rule out systemic bias in a study of this kind.---Sluzzelin 08:32, 27 September 2006 (UTC)

On a somewhat related note, you might be interested in the blonde wig vs helmet study [3] Nil Einne 23:40, 27 September 2006 (UTC)

I really love studies like the one you linked, thanks!---Sluzzelin 16:58, 28 September 2006 (UTC)

It seems to me that the reason is fairly obvious. Since silver is a metallic color, you are in effect adding another layer of metal to the body of the car. Hence it is just stronger than other colors.  :) Dipics 13:38, 29 September 2006 (UTC)

Climate Change

May i please know what is the exact definition of climate change? Also, how does it happen and what are its effects?

Climate change = Long term changes in temperature and precipitation patterns. They can be caused by greenhouse gasses released by burning wood and fossil fuels. Natural cataclysmic events, like supervolcanoes and meteor impacts, also cause such changes. There may also be more subtle natural causes, which are not yet known. StuRat 08:45, 26 September 2006 (UTC)

Have they ever been caused by burning woods and fossil fuels? Every event has been a natural cataclysmic event! What about methane clathrate destabolization. That's a good one. Changes in the sun's intensity. — X [Mac Davis] (SUPERDESK|Help me improve)15:37, 26 September 2006 (UTC)

"Have they ever been caused by burning woods and fossil fuels?" Anyone with even a basic knowledge of chemistry would know that greenhouse gases like CO2 are released by burning wood and fossil fuels. StuRat 17:33, 26 September 2006 (UTC)

I meant climate changes (several degrees) with the main contributer being the burning of woods and fossil fuels. — X [Mac Davis] (SUPERDESK|Help me improve)19:05, 26 September 2006 (UTC)

See Wikipedia's article on climate change. --Shantavira 08:52, 26 September 2006 (UTC)

MacDavis, I could try doing the math, but with such an important subject I'd rather leave that to proper scientists, and they agree that human actions probably cause a global warming of somewhere between 1 and 7 degrees C (with 5 degrees being quite catastrophic). For a more direct response to your question, no, I believe that has never happened before (at least not at this scale). And that is the scary bit. We're not only burning the forests that are present today, but also the ones that have been deposited in fossillised form for millions of years. Did I say millions? Make that hundreds of millions. Volcanoes have pumped CO2 in the atmospere for all that time. Plants have deposited that in the ground over that time and we are now pumping it back in one millionth of that time. A pretty scary experiment. But like I said, ignore me. Listen to the scientists. If they don't know, who does? DirkvdM 19:23, 26 September 2006 (UTC)

I only give much credibility to journal articles now—there seems to be too much bias for or against specific ideas in the global warming tree when you get into the real, heavy paleoclimatology. I am skeptical of this "scary experiment"'s effect, because we just don't know what is going on. You act like it is a simple thing. The plants died and went in the ground and we are putting the plant's carbon into the atmosphere. That is not true, it is a bit more complicated. The carbon cycles can be described as follows:

1. Break the earth into carbon reservoirs. i.e. atmosphere, hydrosphere, biosphere, geosphere, carbonate rocks, fossil fuel deposits, marine sediments—you can go into as much detail as you want.
2. For n reservoirs, there are n-1 carbon fluxes between the selected reservoir and the other reservoirs, combinatorially, (n₂-2n+1) total fluxes.
3. Measure the n₂-2n+1 fluxes, and analyze their chemistries (organic, inorganic, solid, liquid, gas—as much detail as you want)
4. Calculate residence times T for carbon in each reservoir, the mean time an atom of carbon resides in the reservoir. Time is reservoir content C (assumed to be constant, although it is not) over by the sum of rates at which C is added, or the sum of rates at which C is subtracted, to or from other reservoirs. One must be consistent in the use of the reservoirs one defines (Kevin E. Trenberth's research at NCAR is a good example of how not to do this—atmospheric reservoir suddenly turns into all "mobile" C on the planet when calculating T of fossil fuel derived CO₂ in the atmosphere)
5. Take up residence in the nearest padded cell when you find out that most reservoir and flux data are order of magnitude estimates.

Is the burning of plants causing a catastrophic anthropogenic global warming? We all know that during the last 800,000 years that the global climate has changed dramatically many, many times. Just look at the graph of 400,000. Temperatures have fluctuated wildly. Polar ice has gone through dramatic changes. Ice has spread across continents for tens of thousands of years at a time and then melted again. Sea levels have been volatile and varied by as much as 300 feet over the past 800,000 years. Whole land masses, continents, seas and oceans have gone through tremendous changes. The flora, fauna, and wildlife has changed the world over. The deltaCO₂ of 0-65 years ago, and any projected time in the future are insignificant in this relation. — X [Mac Davis] (SUPERDESK|Help me improve)23:35, 26 September 2006 (UTC)

Mac, your "since other things can cause climate change, we must conclude that human activity can't" logic is just, well, garbage. That's like concluding that, since radiation causes cancer, smoking can't also cause cancer. StuRat 03:20, 27 September 2006 (UTC)

But I didn't mean to say that. I meant to say climate change happens anyway, with or without us, and we really don't know what we're talking about if you think it is a simple situation. If I had more space I could have fit more in instead of a short response to two things. Anything in particular? — X [Mac Davis] (SUPERDESK|Help me improve)04:36, 27 September 2006 (UTC)

Here is the logic chain:

• Burning wood and fossil fuels releases CO2 and other greenhouse gases into the air.

• These gases can be demonstrated, in laboratory settings, to cause the greenhouse effect, by allowing sunlight to pass but preventing heat from passing.

• The net effect of this, once greenhouse gases reach a certain level in the atmosphere, will be a rapid increase in global temps.

• This rapid increase in global temps, has, in fact, already been observed.

• A rapid increase in global temps will have a drastic negative effect on human life, by flooding many coastal areas, increasing hurricane numbers and strength, expanding areas of desert, etc.

What portion of this logic do you reject ? That other factors can also cause climate change is completely irrelevant, unless you have some proof that one of those other factors is what's causing the current observations of global warming. StuRat 10:25, 27 September 2006 (UTC)

Personally, I prefer to trust Pres Bush, when he says we have nothing to worry about. After all, he's been so intelligent in all other respects, so how can we doubt him on this ? :-) StuRat 22:39, 26 September 2006 (UTC)

You said it, there have been many climate changes. Which proves it can happen. We also know it wasn't any fun. It led to mass extinctions. And recent findings indicate that they took place in (evolutionary speaking) very short timespans, just hundreds of thousands of years. We may now be causing something similar in just hundreds of years (with the next few decades being bad enough for me to feel some of the effect in my lifetime). The worst one was the Permian-Triassic extinction event, which may have been caused by a rise in temperature of 5 degrees, which in turn caused the release of methane, which caused another 5 degrees rise. Just look at a climate chart to see how habitats will shift over the globe (if they have somewhere to shift to). Also think of the effectst that will have on agriculture (not just climate change but a less predictable weather - a farmer's worst nightmare) and how dependent we are on the high efficiency of agriculture (no room for error). Mankind will probably not go extinct, but it won't be much fun to be alive either. There's an off chance it won't happen (or won't be as bad). But considering the results if it does, is it worth the risk? DirkvdM 09:01, 27 September 2006 (UTC)

But if there have been many natural large-scale changes in global temperature - and looking at the 400,000 year graph that Mac-Davis posted, looks like we're close to a local maximum anyway, there might not be an awful lot we can do about it anyway. That doesn't mean that we shouldn't think about alternative energy sources / saving energy - just that human activity might have only a small part to play in a naturally occurring phenomenon. The Milankovitch cycles, gradual shifts in the positions of Earth's orbit and axis, have been blamed for ice ages - and we're currently at one of the "best" positions in the cycles - low eccentricity, perihelion occuring almost bang on the middle of winter over the largest land-masses, middling obliquity. All these mean that the winters are not very extreme at the moment. Perfect for a relatively warm spell. Richard B 19:15, 27 September 2006 (UTC)

Ok, lets start fresh from the left side again. Logic chain: I am skeptical, and/or reject the last three. It is easier to just talk about them all, rather than one at a time. First thing, EVERY gas blanket in the atmosphere is a GHG. Several factors go into the differently measured "strengths" of the gases. Water vapour, is of course the strongest.

Man, you have no idea (unless you do?) how much controversy there is over almost every study that comes out regarding measures in global temperature, proxy data, albedo records, ice depth, solar insolation, or gas ratio concentration. I could probably hit the bottom of the page with material about this. You have offered no specificity, so I will just answer generally.

All of the "evidence" so far presented for global warming is nothing more than statistical shenanigans. The so-called "experts" have cherry picked their data points and coddled their statistical methods to—lo and behold—arrive at the conclusion they wanted to arrive at.

Examples of the statistical shenanigans?

Examples

This graph was groundbreaking. Until of course in peer review it was found that all of the "evidence" presented was nothing more than statistical shenanigans. The so-called "experts," Shaviv and Veizer, have cherry picked from 12 asteroids and coddled their statistical methods to—lo and behold—arrive at the conclusion they wished to arrive at. Their academic integrity has been lost, by their despicable acts a single paper.

How did you reach this conclusion? If you are talking about the Rahmstorf et al. EOS article, then first, Rahmstorf et al. said that Veizer and Shaviv used 20 meteorites (not 12 as you write). Second, if you look et V&S's response [4], you will see that they used all 80 meteorites which were potassium dated (no cherry picking). (They then average together meteorites which might belong to the same parent body to avoid unreal clustering, and thus use 50 data points, no where close to 12 or 20). Anyway, you should read their reply and see that you shouldn't accept Rahmstorf et al. verbatim. Physicsboy 13:00, 19 October 2006 (UTC)

What? Never heard of it? Well let's do another one.

There is of course, a staple of the environmentalist movement, The Hockeystick. This one has been modified to add Man's impact, but this is the real GRIDA/IPCC graph. For instance, the graph that is the manifestation of anthropogenic global warming. The hockeystick graph. You've all seen it—it is the graph that shows a fairly consistant temperature, but then a huge jump during and after the 1800s, presumably because of increased CO2 emissions by humans because of the Industrial Revolution. However, the monster has been kiled many many many times. There are so many flaws, that make it almost as interesting as swiss cheese. As demonstrated in this graph, the failure is present.

It is a standard temperature/time graph, with four lines and even a shaded "possible error" region around the original hockeystick graph (blue line) produced by Mann and his colleges for the International Panel on Climate Change, GRIDA, and the United Nations. You would think anything from any of those three organizations would be factually accurate, wouldn't you?

The fault is blatant as soon as you understand what the lines mean. As stated, the blue line is the original. This is from real data, collected from around the world, with very advanced paleoclimatological techniques, mostly involving pollen concentration, tree-ring analyzations, and various gas isotope concentration ratios derived from ice cores in the Antarctic and Greenland (see D18O). Sound complicated eh? It gets even more complicated when you find out what they do with the data. With the data they get, they actually change it. They throw out whatever data seems wrong, they add, subtract, multiply, divide, form summations, and work some calculus in, to alter the data. Depending on who it is. In this case, the data they used was, of course, reliable, however the graph-creating algothrim they used to alter the data was not. They worked the data to reach whatever conclusion they want. On the graph, the red line was not from real data, but totally random data. You put the totally random numbers in their algothirm, and out comes the same graph. For good measure, we injected totally random data into NASA's ECHO-G climate modeler, and do you know what came out? Almost the same graph. Even with totally random data, we keep seeing that 2001 was the hottest year in the last thousand. If the data were random, wouldn't the graph be a random graph? Surely not a graph showing a consistent rise in temperature since the Industrial Revolution, exactly like a graph composed of real data.

The meteorological record contains station measurements from thermometers accurate to plus or minus 1 K (2 F); these thermometers are placed in "standard" instrument shelters which are recognizable by any chemical engineer as very inefficient heat exchangers (collected radiant energy is transferred to air moving through the enclosures); the dependence of measured temperature on wind speed is NOT accounted for in the record, is 0.3 K to 1 K above true air temperature at 1 m/s, rises as a function of shelter and thermometer emissivities at lower velocities, and drops off at higher velocities. Wind "shadows" around weather stations have increased over the past century with increased population and the associated building and development activities. The global mean temperature is constructed from a "selection" of station records that swaps stations in and out of the average with few constraints. The Urban heat island effect in recent years has tried to be adjusted out of data, but I'm sure you can see in the article how that has been going.

Taking the Earth's temperature is simply a tough job. We can use satellite measurements or weather balloons though! But why do different data sets in different places say the troposphere is cooling and the surface is warming, and the troposphere is heating and the surface cooling? In fact, even defining precisely what we mean by the absolute surface air temperature is challenging, and how we should do it is. In fact, at the weather stations I talked about in the last paragraph the usual "standard" is to test the temperature would be to have a thermometer 1 m above the ground, measure. Then several meters of the ground, measure. Then several more meters off the ground, and measure. But no body really does that. One is good enough. Current global temperature anomalies (the amount of warming or cooling reported) are estimated against an expected average of 14 °C (57 °F) -- the guess-timated mean temperature over the period 1961-1990. This is usually the 0 "base level" you see on the graphs if you have looked at that many.

CO₂ is strongly correlated to ΔT!

CO₂ is uncorrelated to ΔT!

The temperature record is so thoroughly shot through with errors in method and conservation of method as to be TOTALLY USELESS, therefore, INCONCLUSIVE for any purposes.

Inquire away. I tried not to answer everything, as I don't want to take up too much space. I've done my research on this one. ;) Don't be afraid to fix any code errors for me, as I have got to go. — X [Mac Davis] (SUPERDESK|Help me improve)22:19, 27 September 2006 (UTC)

---

If you're going to dismiss any study on global temps as dishonest stats, let's instead look at something that can't be faked, melting glaciers [5]. I've seen many before and after pics showing greatly reduced glaciers. Can you show me any examples of growing glaciers ? StuRat 18:23, 28 September 2006 (UTC)

Should I waste my time critiquing this? If you wish to discuss real science, no matter what, never use a newspaper article as a source, or to backup a position. I can't go into the reasons why not. I scoured for references, and didn't see any. The before and after pictures of 3 mountain glacier sites in the same place did not give me much proof whatsoever. If you can't find any examples of growing glaciers/thickening ice sheets you didn't look very hard.

The Antarctic region, containing, 90% of the world's iceis getting colder and thicker. Since we are weighting, this bears much greater strength over the roughly six percent of glaciers not found in Antarctica or Greenland (~4%).

But let's not forget Greenland or the other glaciers! Maybe "global" warming only affects the more northern parts of the world?[6] This might be substantiated by this graph, with the green line being the trend line of the Northern hemisphere's trophospheric temperature reading, and the blue line being the Southern hemisphere's trophospheric temperature reading. Observe the difference. The northern hemisphere warms about four times as fast as the southern hemisphere. Not nearly as evenly distributed as one would expect from the greenhouse effect, and it is not because of a CO₂ "backup" in the Northern hemisphere. Now suppose that it was just increase in solar insolation (sunshine)? Can anybody think further?

Going back on topic, Greenland in only one year—2002[7]—by the looks of it, laser altimetry. The ESA has a great section on satellite laser altimetry of Greenland. What? Greenland's glaciers, ice sheet, and ice walls have an positively accelerating growth pattern?[8][9][10] I actually didn't expect this. Several recent papers assert that Greenland's ice is melting, however if you actually do some math with the raw data compiled from a few articles you can find that Greenland's ice is growing in volume—I personally attribute it to the Atlantic Multidecadal Oscillation.

Global glacial mass balance in the last fifty years, reported to the WGMS and NSIDC. The downward trend in the late 1980s is symptomatic of the increased rate and number of retreating glaciers.

Map of mountain glacier mass balance changes since 1970. Thinning in yellow and red, thickening in blue. The 1970's were a decade of more positive mass balance than the 1980-2004 period as seen above.

Data shows the majority of recorded mountain glaciers are melting. These guys are doing a nice job watching one mountain glacier.[11][12]. They think mountain glaciers are mostly melting, which seems to be true based on the data we have. Wikipedia is pretty good about NPOV—and especially compared to this[13]. Compare their mountain glacier mass balance map and graph with our map and graph. The International Panel on Climate Change seems to have left all the growing glaciers out, while still using the same sources *cough cough* That is totally not cherry picking to reach the conclusion—lo and behold—you wanted to reach.

Ice questions answered! More welcome though. I hope the references, footnotes, and links didn't scare you off, they are meant to give extra information if you wanted to learn more (and of course, to prove I'm not making this all up). — X [Mac Davis] (SUPERDESK|Help me improve)07:07, 29 September 2006 (UTC)

I also think it's self-contradictory to say that all the peer-reviewed studies are crap but at the same time state "til of course in peer review it was found that all of the "evidence" presented was nothing more than statistical shenanigans". Peer review is very effective, once it sinks its teeth into the data, at finding flaws in data and theories. There are always examples at shenanigans in science and they can certainly give a bad name to the field in which they occur for the public but not for scientists.

I don't think I said peer-reviewed studies are bad, or peer-review is. I like peer-review! That's why we know these things are wrong. My three examples were not made up by me, peer-review supplied them to me. — X [Mac Davis] (SUPERDESK|Help me improve)07:07, 29 September 2006 (UTC)

I should also point out that "throwing out" data that seems wrong means that, say you have 3000 points on a graph that, when connected, make a nice straight line but one point is completely off. Considering the potential for error, it's more than likely that that one point is a fluke. So you throw it out because it doesn't fit with 99% of the data that's already there, not because it doesn't fit with your theory. AEuSoes1 21:28, 28 September 2006 (UTC)

It can be ok to do that. However the more you do that, the more bias is introduced, intended or unintended—such as what happened with Mann et al.'s hockeystick (actually the algotherm), and several other publications. There is also nothing wrong with using untouched, raw data, or surface air temperature anomaly data. In addition, spikes in data can come from human error, or there could have been an actual spike. — X [Mac Davis] (SUPERDESK|Help me improve)07:07, 29 September 2006 (UTC)

I got the impression that you've rejected peer review since the general scientific consensus is that global warming as described by its proponents is an actually occuring phenomenon. When Al Gore's film (an Inconvenient Truth) came out, oil company spokesmen responded by citing some of the same sources you have regarding antarctic ice getting colder and thicker and the fellow who originally published the find was pretty angry since he demonstrated that this actually helps prove the global warming phenomenon (colder and thicker but with less volume).

I'm not surprised—all but one of the citations were pro-warming I believe. I don't know why an author would be angry, I don't think anybody lied—they just interpreted the data differently. I am not sure how many said there was more ice but less volume. You might be intersted in footnote number eleven. — X [Mac Davis] (SUPERDESK|Help me improve)17:17, 29 September 2006 (UTC)

While correlation between human activity and global warming is more controversial (especially outside the scientific community; 928 peer-reviewed scientific articles on global climate change published between 1993 and 2003 never questioned the human impact) the fact of the matter is that it's something we all would rather not happen and if human beings are not making it worse, we can still do something to make it better.

Oreskes's activity had a few faults. I do not believe he explained the statistical methods in which he selected the abstracts. The rest are explained in the following links, and thus, I conclude his activity does not stand up to scientific scrutiny.[14][15][16] I don't see why a flawed argument toward argumentum ad populum is doing here either. — X [Mac Davis] (SUPERDESK|Help me improve)17:17, 29 September 2006 (UTC)

Also, I'm not sure why you said that every gas blanket in the atmosphere is a greenhouse gas. That's simply not true. Atmospheric nitrogen, for example, is not. AEuSoes1 12:28, 29 September 2006 (UTC)

Nitrogen's is fairly insignificant, because "of their symmetry these vibrations [from absorbed IR] do not create any transient charge separation that enhances the interaction with radiation." (Greenhouse effect) — X [Mac Davis] (SUPERDESK|Help me improve)17:17, 29 September 2006 (UTC)

The link I gave... as well as the ones you provided, lay it out. Do you read the links? Oreskes is a woman. She searched the ISI database for "global climate change" and deleted a handful of articles that didn't actually talk about climate change. Even the Wikipedia article list of scientists opposing global warming consensus states that no scientists have expressed doubt that the Earth is warming.

Thicker ice doesn't mean there's more ice when the glaciers are shrinking. I haven't read the study (and I know you haven't) but I believe it has something to do with increased snowfall over the polar caps due to higher precipitation due to warmer temperatures at the lower latitudes. I'm sure the author was angry because the spokesman cited results of the study without qualifying that the author of said study actually came to the opposite conclusion than he was espousing, which is intellectually dishonest at best and more than likely flat out deceptive.

Why is saying that climate change will bring undesirable results argumentum ad populum? Or do you mean that mentioning overwhelming consensus in the scientific community? That's actually an appeal to authority and since scientists know what they're talking about and are rigorously peer-reviewed, you're hard-pressed to show that such an appeal is illigitimate.

We should probably move this discussion to our respective talk pages if it's going to last much longer than this. AEuSoes1 21:23, 30 September 2006 (UTC)

For the record, the "he" was a typo. We discussed it further on our respective talk pages, and this message is posted about an month and a half later. X [Mac Davis] (DESK|How's my driving?) 06:46, 13 November 2006 (UTC)

Mac, all those stats seemed to just be you admitting that mountain glaciers are thinning dramatically, on average, around the world. If you don't think this is due to global warming, what is causing it, exactly ? As for Greenland, it seems to be losing glaciers in some places and growing them in others. I attribute this to the weakening of the Gulf Stream, one predicted consequence of global warming. Also, if you need to write this much material, you should put it on your talk page and refer us there. These Ref Desk pages are already too big. StuRat 12:34, 30 September 2006 (UTC)

For the record, sorry, I didn't come back after Aeusoes's reply. But to answer your questions (breifly :)), I don't know what is causing moutain glaciers to disproportionally melt compared to Greenland (more even), and Antarctica. Although I have not done any research into it, I conjecture that precipitation, size, and location are the major factors. I stuck an external link with an unaesthetically-pleasing graph showing warming trends in the Northern and Souther Hemispheres. IPCC GRIDA and us both used the same data on our maps, and you can see that the majority of mountain glacier data we used was from the Northern Hemisphere. Get what I'm trying to say? I am pretty sure we don't have any good precipitation data to compare to the recent glacier trends to though. :( Maybe in the future. X [Mac Davis] (DESK|How's my driving?) 06:46, 13 November 2006 (UTC)

Appearance of lights when short-sighted

I "suffer" from myopia, or shortsightedness, and I've always noticed that without my glasses on, bright lights appear as kinda cross-hatched, hazy circles against the background, larger than the actual light and dimmer. I always wondered about this, and I just now read in the article on bokeh (artistically blurring a photograph): "When a lens is stopped down to something other than its maximum aperture, out-of-focus points are blurred into the polygonal shape of the aperture rather than perfect circles" Is this an explanation of why lights appear that way to my out-of-focus eyes? Does anyone else with glasses experience this? Sum0 11:58, 26 September 2006 (UTC)

i have myopia too. And i often find traffic lights blurrying, with the light forming a cross shape and if i squint, the four 'bits' of the cross get longer and more blurred. I recall asking my optometrist about it once and he told me it's not actually because of short-sightness, but rather, due to Astigmatism, although it tends to be not so obvious in people who have astigmatism but otherwise normal vision.

although...if it only happens when you are wearing glasses, it could also be a problem with your glasses. So things like having the wrong prescription, or having the two lens not matched up (if your two eyes are not the same), having really dirty glasses, or wearing them in the wrong spot (i.e. if they are falling too low down) etc. Is the blurring any better when you are wearing contact lens instead of glasses? --Yaksha 12:14, 26 September 2006 (UTC)

Thanks for the answer. I only really get the effect when I'm not wearing my glasses. Actually, when I used to wear contact lenses I noticed an effect where there was a "halo" around bright lights... Sum0 13:08, 26 September 2006 (UTC)

Before my eye surgery, lights looked like a beehive pattern to me. With eye surgery, they have a strong glare - making it difficult to drive at night. --Kainaw ^(talk) 13:19, 26 September 2006 (UTC)

i don't get any halos around bright lights, but the blurring doesn't happen when i'm wearing contacts. It happens if i squint when i'm wearing glasses, but most when i'm not wearing anything at all. Which makes sense because both prescription glasses and contact lens can correct astigmatism. --Yaksha 13:29, 26 September 2006 (UTC)

Perhaps we should ask the Bush administration...they all seem to be rather shortsighted. :-) StuRat 17:22, 26 September 2006 (UTC)

Really? I thought they were blind, deaf and especially dumb. Clarityfiend 06:58, 27 September 2006 (UTC)

Psychology question: name of syndrome

I'm trying to learn more about a syndrome I once heard mentioned but which I'm not sure how to spell, and therefore can't find more about. It sounds something like "DeClarenbeau" syndrome and had to do with one sufferer travelling to Buckingham Palace in belief that a royal was secretly communicating with them via the window shutters or something. Sorry to be so vague, but this is really bothering me. --65.92.51.239 13:27, 26 September 2006 (UTC)

I'm sure there is a name for a syndrome where you make up bizarre syndromes but this one does exist: de Clerambault syndrome. Although it is not limited to royalty maybe you are thinking of the Michael Fagan incident. MeltBanana 14:33, 26 September 2006 (UTC)

That's it! Thank you very much. --65.92.51.239 22:16, 26 September 2006 (UTC)

Vision at speed of light

If a human being could withstand travelling at light speed and had a) a device that would propel him at that speed and b) an area without obstacles of infinite length and width... what would he be able to see? In a car travelling at (say) 70mph, objects nearby seem blurred, but you can easily focus on distant features, such as mountains. Would this be possible if the objects were suitably far away (say, a star)? Or would the fact that the light that makes vision possible is being exceeded create problems for the eyes/brain? --Dweller 13:47, 26 September 2006 (UTC)

From the photon's point of view everything else is still. If you were travelling at the speed of light and had a mirror, what would you see? There would be an image of yourself in the mirror that you see. — X [Mac Davis] (SUPERDESK|Help me improve)15:34, 26 September 2006 (UTC)

Actually, you wouldn't see anything, because you wouldn't have time to see anything. Or to notice that you weren't seeing anything. A particle going the speed of light experiences no duration. --Trovatore 19:24, 26 September 2006 (UTC)

Our experience of time is indepent of location, the fact that the particle doesn't experience duration doesn't matter, the observator does. Mion 20:44, 26 September 2006 (UTC)

That would mean you're not travelling at the speed of light, the light has to get past you, reflect in the mirror, to your eyes, if you would keep the mirror behind you, yes. Mion 15:47, 26 September 2006 (UTC)

It's impossible for a massive being (massive = "having mass") to travel at the speed of light. If you were traveling at 99% the speed of light, however, (a) you would still observe that the speed of the light you measure is travelling at c (don't ask why - it's extraordinarily complicated) and (b) I think the light you observe would be shifted very much towards the red or blue (depend on the direction it is travelling). Raul654 15:50, 26 September 2006 (UTC)

So in summary I'd see red / blue mountains but I wouldn't be able to see myself in a rear-view mirror? --Dweller 15:58, 26 September 2006 (UTC)

You would be able to see yourself. According to Einstein, you always observe light traveling at the same speed (the exact figure depending on the medium, in this case air) regardless of how fast you're moving. So it's not as if light from behind can't overtake you. Because of doppler shift, there would probably be less visible light, but you wouldn't turn into Hellen Keller. Clarityfiend 16:50, 26 September 2006 (UTC)

No, : (doppler shift) such as light or gravity in special relativity only the relative difference in velocity between the observer and the source needs to be considered.

relative difference in velocity is zero in this case, you travel exact at the same speed.Mion 17:42, 26 September 2006 (UTC)

off course, Einstein is right, what changes is the own observation, and thats what we are talking about here.Mion 17:47, 26 September 2006 (UTC)

First off, I'm talking about going slower than the speed of light. Given that, the second postulate of special relativity means that the observer always sees light coming at him from all directions at the same speed - there is always what you call a "relative difference in velocity". In fact, if you check the article, it explicits says so (it was there before, I swear!). It's a counterintuitive notion, but true as far as we can tell. Clarityfiend 17:58, 26 September 2006 (UTC)

Dweller requested the same speed, but if there is a difference in speed (only if you go slower, not faster) off course you can see light coming from all directions. Mion 18:18, 26 September 2006 (UTC)

Not with light coming from your back, you can have sidelight, which included with the mirror angle is shorter than from the back.Mion 16:09, 26 September 2006 (UTC)

eh? --Dweller 17:19, 26 September 2006 (UTC)

Would that mean that in a vacuum state, if you look backwarts you see nothing, including te range to the left and right. until the angle is reached ? whereas the color range is in the real state, created by the wavelenghts of light, which travel at the same speed, but have different influences (by gravity or electromagnetic force). Mion 16:30, 26 September 2006 (UTC)

and, erm, eh? --Dweller 17:19, 26 September 2006 (UTC)

At all speeds slower than the speed of light, you would see perfectly normally (though your brain might have trouble processing it). At the speed of light, you would only be able to see a narrow angle in front of you unless you stuck your head out the window and moved it slightly in the direction you want to see, then you might pick up a few photons. Some other interesting effects of lightspeed travel: if someone in the back seat had a flashlight you wouldn't be able to see it (since addition of velocities doesn't apply to light)- in fact, you wouldn't see the back seat at all. Also if you dropped a ball bearing out the window at that speed it could probably destroy a city :D --froth^{T C} 19:20, 26 September 2006 (UTC)

Your brain works exact on the speed of light and at that velocity it would be a 1 on 1 intake, a bit heavy and no time for other thoughts. Mion 19:24, 26 September 2006 (UTC)

Brains do not work at the speed of light --froth^{T C} 20:40, 26 September 2006 (UTC)

I know it is cheating [[17]], you are right, light is a considerable faster.Mion 21:25, 26 September 2006 (UTC)

Why would your brain have trouble? Other than experiencing the sheer terror of wondering when you were going to hit a dust particle. Clarityfiend 01:01, 27 September 2006 (UTC)

Then again you wouldn't exist because of the mass gain while approaching c. — X [Mac Davis] (SUPERDESK|Help me improve)02:00, 27 September 2006 (UTC)

Gosh. I didn't realise I'd asked such an apparently difficult question! I think what you're saying is:

• I need to add to the stipulations in the question, an assumption that a human could withstand travel at that speed
• I would see relatively normally on a narrow front looking forwards
• That vision may be coloured
• Looking sideways/backwards I would see little/nothing
• I probably shouldn't litter

Does that sum it up? --Dweller 09:19, 27 September 2006 (UTC)

No. In the first place, unless you want to annoy Uncle Albert greatly, anything with mass cannot travel at the speed of light, never, never never. (This means you! Unless you go on a very strict diet.) However, if you could satisfy your lust for speed by going a mere 0.999999c, then you would be able to see in all directions. However, the Doppler effect would change the colors and intensities of what you see. BUT you definitely should not litter, especially in outer space. If someone else travelling at near-light speed runs into your gum wrapper, you could be sued up the wazzoo. Clarityfiend 08:16, 28 September 2006 (UTC)

So light can only travel at the speed of light becuase its so light-- in fact totally massless?--Light current 16:27, 28 September 2006 (UTC)

Yes. But you should already know this, Light current! *sighs* The younger generation - always forgetting its heritage. Clarityfiend 02:17, 29 September 2006 (UTC)

Luxons, Tachyons, and ... something yons may be of interest.— X [Mac Davis] (SUPERDESK|Help me improve)08:04, 29 September 2006 (UTC)

You would see everything that ever happened (and ever will happen) in the universe all happen at exactly the same time at exactly the same point.

Whoa, far out dude. that's heavy. (relatively speaking) Mattopaedia 04:48, 30 September 2006 (UTC)

Movement at the speed of light and beyond it.

I was wondering what would happen IF(negating any scientific/physic arguments) someone could move at the speed of light and beyond.

from what I managed to think of(without much knowledge about this specific topic) It would be something like this:

Required knowledge:

In the view of the humans the quickest and most common way to perceive movement is to use your eyes to see. what we see are actual broken rays of light that diffused upon contact with the obstacle. if someone moves then the light will be broken in another way and we will be able to see the difference because we see in "frames" just like on a computer displays images and movies. but here comes the tricky part. If someone moves at the speed of light then his light will be broken at the spot he moved upon and ?every? spot between the previous spot and the new spot. question: or is it only broken on the original and the ending spot? and therefore the movement will seem instantanious for us with the person/object on both the spots at the same time (at least in that frame which will vanish too quick for us to actually be aware of it but still).

 _______  in this frame the 
|1)     | o (=object/person) 
|       | is still standing 
| 0     | still and this
|       | is our 
|       | starting point

Humans do not see in frames. Melchoir 16:58, 26 September 2006 (UTC)

It was my understanding that what we see is in fact a sequence of images, each "taken" over a period of time of about 1/16 of a second. This can be seen in the length of the blur of a fluorescent object placed under intermittent (strobe or AC-driven fluorescent) light. Of course, these frames are not a few milliseconds long but separated by scores of milliseconds the way film is (right?), but they are frames nonetheless. Am I misled? --Tardis 20:11, 26 September 2006 (UTC)

'Fraid so. See Persistence of vision and Flicker fusion threshold. Although there are important characteristic timescales associated with vision, the visual system does not operate a repeating process at any frequency. If it did, then when observing periodic scenes, you'd start to notice aliasing artifacts at the beat frequency. I don't know what you're saying about intermittent lighting; whatever happens there is a result of the light, not the eye. Melchoir 20:24, 26 September 2006 (UTC)

Er, yeah -- the lighting thing was way off. I was actually thinking (or trying to think) more of an object only momentarily in view, and changing (e.g., two images each displayed for n ms, or one object being moved by the observer at high speed) -- then, if there were frames, at some speeds/durations we would always see two different images (one image and then the other, or the object over here and then over there) whereas at others we would see (at least on some occurrences, when it fell within a frame) exactly one mixed image (the object streaking all the way across the viewfield, or both images superimposed) such that we could not determine any ordering within it (which image was first, or which way the object was moving). But it's pretty clear from those articles that doing this experiment would not produce those results! I'm not sure about your aliasing point, though, because of the 'smearing out' I was attributing to the frames -- perhaps some subtle form would occur, though? Perhaps a stick rotating about one end would appear at certain frequencies to be a top "half-circle-of-stick" and a bottom one alternating. In any case, thanks for pointing that out. --Tardis 22:18, 26 September 2006 (UTC)

Yeah, the stick thing is basically what I had in mind. You probably wouldn't see a textbook computer aliasing pattern, but there'd be... something. Melchoir 22:23, 26 September 2006 (UTC)

This discussion prompted me to find this link, which answers a question about humans-seeing-in-frames that I had. I thought I'd post it in case others hadn't seen it. --Allen 02:33, 27 September 2006 (UTC)

So why do we see things like helicopter rotor blades and car wheel hubs follow that strange pattern where they spin up faster and faster, then disappear, and then the blurred mess seems to coalesce again and slowly starts spinning back the other way? Maelin 11:02, 29 September 2006 (UTC)

Im sorry I didnt have the chance to finish this question before but I'll finish this now.

 _______  in this frame the 
|1)     | o (=object/person) 
|       | is still standing 
| 0     | still and this
|       | is our 
|       | starting point

 _______  in this frame the 
|2)     | o (=object/person) 
|       | is moving at a "normal" rate 
|   0   | and his light is
|       | broken at the
|       | new location. so far so good and clear.

_______________________________________________________________________

 _______  in this frame the 
|1)     | o (=object/person) 
|       | is still standing 
| 0     | still and this
|       | is our 
|       | starting point

 _______  in this frame the 
|2)     | o (=object/person) 
|       | is moving at the speed of 
| 0  0  | light and therefore has his 
|       | light broken on both locations
|       | but is not physcially present on the original spot

_________________________________________________________________________________

 _______  in this frame the 
|1)     | o (=object/person) 
|       | is still standing 
| 0     | still and this
|       | is our 
|       | starting point

________  in this frame the 
|0)     | o (=object/person) 
|       | has moven faster than 
|    0  | the speed of light and 
|       | therefore went back in 
|       | time as we perceive it? andthus he added another object in our frame that was added  
          later on. manipulating our memory as well?

 _______  in this frame the 
|1)     | o (=object/person) 
|       | is still standing 
| 0  0  | still but because he 
|       | went faster than the speed 
|       | of light he will be there twice. this time physical on both locations? 

_______  in this frame the 
|2)     | o (=object/person) 
|       | has arrived on the location
|    0  | ***
|       | *** 
|       | ***

_____________________________________________________________

although greatly simplified and ignoring the normal restraints this raises a lot of questions and contra-arguments. which I would be thrilled to hear.

Cellphones and Cancer?

Does anybody know the corralations between cell phone use and cancer? If anybody knows any good stats links, that would be nice. HP 50g 16:52, 26 September 2006 (UTC)

Try Mobile phone radiation and health. --Allen 17:43, 26 September 2006 (UTC)

Oh...nice! Didin't even notice that. Thanks :) HP 50g 20:09, 26 September 2006 (UTC)

How long is a moment

Hi There :

I was recently told that a "moment" is actually 90 seconds, it being an old English term, is this true ? I cannot find a reference to it any where. Thanks

You might want to try Wikipedia:Reference desk/Language instead... Melchoir 18:29, 26 September 2006 (UTC)

A moment is exactly 42 milliseconds. :) ☢ Ҡi∊ff⌇↯ 18:33, 26 September 2006 (UTC)

From the OED: In mediæval reckoning, the tenth part of a ‘point’, [thus] the fortieth or the fiftieth part of an hour.--Shantavira 18:47, 26 September 2006 (UTC)

Thank God for the decimal system. Actually, strike that. Thank ourselves. DirkvdM 19:07, 26 September 2006 (UTC)

That's right. God gave us the English system. It was mere mortals who devised the metric system. alteripse 19:54, 26 September 2006 (UTC)

God gave us Shekels and baths. Surprisingly the "bath" unit of measure doesn't have its own article on wikipedia --froth^{T C} 21:19, 27 September 2006 (UTC)

Although, I have to say that working out compound interest on £107, 9 shillings and 7 pence halfpenny was rather tiresome. JackofOz 20:00, 26 September 2006 (UTC)

In common usage, it can be the same as an instant, i.e. a split second. Or it can be a specific point in time, or a longer period at some specific era. Edison 14:46, 27 September 2006 (UTC)

Brain injury

Nursing management of brain injurySansonala@sify·com 18:39, 26 September 2006 (UTC)soniya

Suitly emphazi? Hyenaste ^(tell) 18:45, 26 September 2006 (UTC)

Try Wikipedia's article on brain injury.--Shantavira 18:52, 26 September 2006 (UTC)

Oh, and contact the local brain surgeon with your query, too, since he will be able to diagnose your particular brain injury and offer solid advice. Hyenaste ^(tell) 19:16, 26 September 2006 (UTC)

I think the poster might be looking for information on how to care for someone with a brain injury. I can't find a whole lot on the internet that looks very good, but here's something: [18], [19]. --Allen 19:59, 26 September 2006 (UTC)

The article Shantavira linked to on brain injury is a good start. But otherwise, we (and wikipedia in general) does not give medical advice. In your best interests, i recommend you consult a properly qualified doctor. --Yaksha 07:41, 27 September 2006 (UTC)

Oh god, not another speed of light question... :(

OK so lets say some friends and I drive out towards some empty region of space for this little experiment. One of my friends, she has a beam or orb or whatever, is emitting light. If she shines the light at me, then, on the count of three, we start moving away from each other at more than 50% c, what do I see? Nothing, right? Our combined speed is greater than c even though we are both traveling significantly slower. But I asked because light is a fickle dame and she never behaves as I expect her to. Hyenaste ^(tell) 19:20, 26 September 2006 (UTC)

Almost exactly answered here. A more interesting question would be defeating causality by travelling to your destination at 60% c while your destination travels towards you at 60% c, though that problem is kind of answered here and better answered here --froth^{T C} 19:29, 26 September 2006 (UTC)

No, you would see the light. And, from the POV of you, your friend is not moving away at greater than c; once relativity comes into play, velocity vectors do not add arithmetically. You might want to look up Special relativity, Velocity-addition formula and Introduction to special relativity. Einstein's ideas, even though now more than 100 years old, are fiendishly complex, so do not be downhearted that you do not yet fully understand them! Batmanand | Talk 19:35, 26 September 2006 (UTC)

Oh jeez. Complex is right. So I would see her going 99.5% or so the speed of light, but my friends waiting where we started would still see her travelling at 60%, right? Hyenaste ^(tell) 19:45, 26 September 2006 (UTC)

Precisely. In fact, it's by definition that your friends say that: your initial statement that each of you is moving away at >.5c was implicitly putting the problem in terms of an observer like the friends you describe. Velocity is always relative; it's only they who can even formulate the apparent paradox. (Of course, your friends have to agree with you on the question of whether you can see the light: they will still see her light moving toward you at c, which is faster than you're going, so it catches up to you.) --Tardis 20:15, 26 September 2006 (UTC)

Ah, I get it. I'm not really going at .6c, I'm only going that speed relative to the observers. If a ray of light passed her from behind, it will eventually catch up to me even if I were going c - 1m/s, and that ray will ride alongside her rays. That makes perfect sense. Just to make sure, the midpoint observers will see the light before I do, right? Hyenaste ^(tell) 20:59, 26 September 2006 (UTC)

Yes -- so long as they are close to the midpoint of the line between you and the light, they will see it before you do -- but remember that in general (though not in this case), the idea of one event happening before or after another is also observer-dependent: this is the relativity of simultaneity. --Tardis 14:35, 27 September 2006 (UTC)

Would the light not be severely red-shifted, by how much?

Yes -- use the velocity-addition formula and then the relativistic Doppler effect formula. Alternatively, use the Doppler formula twice -- once to get back into the frame in which the velocities were derived, and then again to get into the other person's frame. (Of course, this implies (correctly) that the Doppler formula and the velocity formula are equivalent in a sense.) --Tardis 22:19, 28 September 2006 (UTC)

Climate Change and the speed of light

If a seagull is flying at .99 c while emitting considerable amounts of CO2 does it have more or less effect on the environment than a magpie flying at exactly 1.0 c?

Laden or unladen? --Trovatore 19:39, 26 September 2006 (UTC)

African or European? Batmanand | Talk 19:42, 26 September 2006 (UTC)

It would burn up in the atmosphere... This is eerily relevant --froth^{T C} 20:46, 26 September 2006 (UTC)

No that only applies to supersonic eagles! 8-)

With that kind of kinetic energy, it might not burn up in the atmosphere so much as just burn up the atmosphere. --Allen 21:14, 26 September 2006 (UTC)

Nah. There isn't much mechanical energy coupled through gases. Instead there'd just be a big wind, the kind which pushes down entire forests. There also might be a big flash, the kind which melts entire deserts into green glass.

Oh yeah, I was going to write that but I got distracted by that article I linked o_O ... anyway in retrospect it seems kind of unlikely --froth^{T C} 22:31, 26 September 2006 (UTC)

Who cares? 8-)--Light current 01:47, 27 September 2006 (UTC)

I think that the answer can be summed up by the radical expression ${\sqrt {(}}France)$ Deltacom1515 21:14, 27 September 2006 (UTC)

Well, the magpie is blacker than the gull, so it sinks carbon faster. -- Fuzzyeric 04:33, 28 September 2006 (UTC)

Hmmm....

or

--Russoc4 20:42, 26 September 2006 (UTC)

Are you kidding? Front. --froth^{T C} 20:47, 26 September 2006 (UTC)

Overhand, of course. Otherwise it's virtually impossible to tear it off with a simple tug. -- Plutortalkcontribs 20:49, 26 September 2006 (UTC)

. Hyenaste ^(tell) 20:51, 26 September 2006 (UTC)

good idea :D --froth^{T C} 20:55, 26 September 2006 (UTC)

Melchoir 21:00, 26 September 2006 (UTC)

Support, mainly for aesthetic reasons. It just looks right. --Allen 21:09, 26 September 2006 (UTC)

Haha! :-) —Bromskloss 21:42, 26 September 2006 (UTC)

- The friction on the wall prevents free roll.Mion 21:50, 26 September 2006 (UTC)

I don't want wall-friction-bits on my toilet paper, thank you. —Pengo ^{talk · contribs} 09:40, 27 September 2006 (UTC)

There might be a lid (or whatever it's called), not included in the drawings. —Bromskloss 22:12, 26 September 2006 (UTC)

Not to mention that that argument only makes sense if defending the overhand mount.. --froth^{T C} 03:03, 27 September 2006 (UTC)

the roll gives you something to push against when you're tearing off the paper. The other way round, you need to hold down the roll with your hand when you're tearing. --woggly 14:02, 27 September 2006 (UTC)

If the edge of the paper is hidden, then with front-facing rolls if we whack the roll hard in order to let air friction start it unrolling, the unrolled paper is obvious, and we can grab the roll to stop it instantly. But when giving back-facing rolls a whack, usually the paper starts unrolling inside the holder, then gets ejected as a packed wad with several feet of paper. It requires re-rolling in order to find the end. Front-facing rolls don't behave that way.--Wjbeaty 01:44, 28 September 2006 (UTC)

I wonder if there's a correlation between this question and laying down one's sandwiches backwards... Melchoir 22:25, 26 September 2006 (UTC)

Friction on the wall? Wtf... if you have friction from the backwards mounting, then there is going to be friction in an overhand mounting. The roll is still in the same spot, either against the wall or not.--Russoc4 23:19, 26 September 2006 (UTC)

There's 1 more toilet paper thickness between the roll and the wall using the backwards mount. I don't know about you, but I use two-ply and that makes a difference. It still doesn't make up for the incredible ease-of-use of the overhand mount --froth^{T C} 03:01, 27 September 2006 (UTC)

Science has not come to a definitive conclusion on this issue. Research is ongoing in universities and research labs throughout the world. --GangofOne 23:13, 26 September 2006 (UTC)

Finished the research with it, someone has a new roll ? and hurry....Mion 23:39, 26 September 2006 (UTC)

---

But what about

• Nominate and support — X [Mac Davis] (SUPERDESK|Help me improve)23:43, 26 September 2006 (UTC)

I feel greatly in dept here, for saving my life.Mion 23:45, 26 September 2006 (UTC)

Eh. I could have taken that in a bad way if I was that sensitive. Heh. At least you didn't need a fucking matching histocompatability complex. — X [Mac Davis] (SUPERDESK|Help me improve)23:56, 26 September 2006 (UTC)

As always, you have saved the day Mr. Mac Davis...--Russoc4 03:12, 27 September 2006 (UTC)

I have a cat, front isn't safe with her around. Back AEuSoes1 03:54, 28 September 2006 (UTC)

That's the first reasonable argument in support of back. Nevertheless: ! Simon A. 09:26, 28 September 2006 (UTC)

- Makes it harder for the kids to unroll the whole lot in one go when toilet training. Mattopaedia 05:00, 30 September 2006 (UTC)

Speed of light =)

If, for example, a swallow was just flying around through the heliosphere at nearly the speed of light, would the density of the solar wind be high enough to cause enough friction to appreciably heat up the bird (similar to the effect of atmospheric gasses on much-slower-moving spacecraft during reentry)? Assuming the poor fellow somehow powers through the bow shock, how about the interstellar medium? The intergalactic medium? --froth^{T C} 20:54, 26 September 2006 (UTC)

By the way, this is a serious question that could have ramifications for interstellar space travel --froth^{T C} 22:14, 26 September 2006 (UTC)

Just using my intuition I'd say: the bird is toast. Maybe it's not a good idea for spacecraft to cruise at near lightspeed in the proximity of stars. --Lambiam^Talk 00:10, 27 September 2006 (UTC)

It's quite a strange question. I don't consider the model any natural. 1) What causes the bird to have a curved trajectory? 2) It seems to me, that the bird would emit more light (thermal radiation) than it would swallow. 62.63.76.51 00:23, 27 September 2006 (UTC)

I'd say NASA needs to do some more ceramic work. Mattopaedia 05:09, 30 September 2006 (UTC)