John Cuthber

If the religious dogma contradicts itself, does that make the problem even worse?

Good point about urea from other sources. The problem with the UV is that it will also light up some plant based materials (chlorophyll and carotenes fluoresce too, Come to think of it, so do some rocks). Equally, it won't distinguish bird droppings being washed through from the roof. Creatinine is a reasonable choice, but it's not trivial to test for.

It would be possible, you just need a bigger magnet, which would be expensive.

Really? Cool! Can you describe the stable stationary system of magnets that hovers in the earth's gravitational field please? Remember, no spinning, no diamagnetics, no tethers. Just a simple diagram will do. Thanks

"To summarise, the point of my query was questioning whether or not a single battery is in effect an infinite number of very much smaller batteries in parallel?" Yes, it is (well, not strictly infinite- you can't have a battery with half a molecule or half an atom), but the number is huge). However,unlike getting a bunch of batteries in separate boxes and connecting them, the individual parallel cells are small, so if one reverse charges another it's not going to matter much. All of them are very nearly identical. (if you are going to put batteries in parallel, make sure that they are all the same brand, same age and so on. Also they all share the same thermal environment. If one part of the cell starts delivering more than its share of the current then the electrolyte in the vicinity is heated up and so it is held in check a bit. If you have two separate cells and one warms up a bit its internal resistance falls a bit and so it delivers more current so it warms up a bit more. At the least, this means it goes flat before the other one, and that's a problem.

Nope, you can't do that until you can either defend or retract the controversial statement you made. (It's part of the rules here) How do you decide to believe something which isn't true? How do you, for example, decide to believe I'm a butterfly? Or are you finally accepting that you were simply wrong when you said "deciding to believe in something one knows is not true isn't a sign of mental illness. It is a sign of humanity. "?

"Saying that everybody believes things that they know is wrong doesn't imply that I believe you're a butterfly, now does it?" Nobody said it did. But this (which is what you said earlier) "deciding to believe in something one knows is not true isn't a sign of mental illness. It is a sign of humanity. " implies that you could believe it if you chose to. I'm asking how you would do that. I'm not on about believing things that are not true. I'm asking how you decide to believe in something which you know to be false. For example, if you decided to believe that I'm a butterfly (perhaps because someone offered you a lot of money to believe it), how would you do it?

"Do you need a few billion affidavits?" No, just an answer. Since you think it's self evident how you can convince yourself that I'm a butterfly, surely you ought to be able to show it. How do you do it? People fool themselves a lot- but not generally deliberately. How do you do that? "People keep two sets of books." Yes, but if they truly believed in the figures, they would only need one book. "Believing that the ground is occasionally static beneath your feet just makes you human." No, it means that it is static in my frame of reference to a good enough approximation for the job in hand. So, once more. How would you go about deciding to believe that I am a cabbage white butterfly? Seriously, what would you do in order to be able to pass the lie detector test while asserting that I'm a butterfly (Pieris brassicae to my friends)? For the moment, let's assume there is a lie detector that actually works.

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

For reasons unlikely to ever become clear, I researched this a while ago. The answer is to look for urea.The simplest way is to use urease to convert the urea to ammonia and measure that. There are details in this book http://books.google.co.uk/books?id=Rot4VXFa27IC&q=urease#search_anchor

My guess is that there may be an "explanation" but it won't explain anything so you might as well lock the thread. Of course, I might be wrong.

You didn't: Klaynos did

"It makes no sense whats so ever to me." Sorry to be the one to tell you this, but the universe doesn't know what makes sense to you and is under no obligation whatsoever to act in a way that you think makes sense.

I wouldn't use IR as a first choice. Water absorbs a lot of IR so it restricts the range of frequencies that you can use to look for impurities. Also IR isn't very sensitive. If you are just going to use a spectrometer then UV would be better. However, the real deciding factor is what sort of chemicals or pollutants you are looking for.

What I'm doing is asking you to demonstrate, or, at least, explain an unevinced assertion which you made earlier. You said "deciding to believe in something one knows is not true" isn't a sign of mental illness. It is a sign of humanity. ". OK, It's completely obvious that I am not a butterfly. (That's why I chose a butterfly as an example). so it is " something one knows is not true" and you say that "deciding to believe in something one knows is not true ... is a sign of humanity". So, how do you go about deciding to believe that it is true? If you can not do that, is it because you are not human or is it that you were wrong about humans?

If, as is entirely reasonable, the bacteria are hiding inside the particles of stuff in the water they are safe from UV. (at least, they are if the particles are opaque to the UV, and that's not a bad bet if they look dark.) This http://en.wikipedia.org/wiki/Solar_water_disinfection essentially cooks them- just like the microwave. Also, what happens to microwaves in water isn't the same as the skin depth in electronics- it's a resonance phenomenon. Water is pretty nearly an insulator. so the "skin depth" would be near infinite. So the term "skin depth" isn't really applicable. http://en.wikipedia.org/wiki/Penetration_depth is better

" Clearly neither of us thinks that everybody who goes to church is mental. " It is, indeed, clear. Yet you said that I did think that.(strictly, what you said was " I can only try to dissuade you from your belief that all church going folk are insane " But I never had that belief. So it was a strawman attack. That's what I was arguing about. You said I said something which I didn't actually say. You lied about what I said. That's not an unreasonable thing to argue against. You said "deciding to believe in something one knows is not true" isn't a sign of mental illness. It is a sign of humanity. " OK you know that I'm not a butterfly- because butterflies don't have internet access and so on. Now, if believing things that are not true is part of humanity then you, as a human, should be able to decide to believe something that's not true (like the idea that I'm an insect) So,. how do you do that? How do you choose to believe that? BTW, re "And I don't know what cabbage white butterfly even means." FFS I even gave you the Latin name for it. Are you too lazy to Google it? Anyway, if you can't believe that I'm an insect then how can you say that it's a human trait to believe things

"Incidentally, Earnshaw's so-called "theorem" suppose no other action in the world. Just a gravity field (something difficult to get rid of on Earth) makes this "theorem" unapplicable, and indeed magnets float over superconductors, stably thanks to gravity." LOL ​In the absence of a gravitational field things would hover anyway. Earnshaw's theory is, in fact, true. It is impossible for you to get a stable system where a magnet float in space. Diamagnetism (with or without superconductors) require moving electrons so , as there are moving parts, it's not stable. An AC system is also, clearly not "stable" in two sense, firstly the suspended item moves with the varying field. Secondly, it requires the dissipation of energy. If it was truly stable it would be a perpetual motion machine. So, perhaps, before you say a theory isn't true, you should check to see what the theory applies to. That way you won't cite counter examples which are outside its scope. In much the same way, unless you can actually answer the original question of the thread by showing how to float a hovercraft on the Earth's magnetic field, you haven't really added much.

Well, what you said was ". I can only try to dissuade you from your belief that all church going folk are insane " And that's a strawman because I never said (or even thought) that "all church going folk are insane" I never had the belief that you say you are trying to dissuade me from. Second point "Go ahead and show me where I said that. Go ahead and quote that" I never said that you had said that all church goers were insane. It's another of your strawmen. Do you understand that? Good, Now you can try answering my question (I think this is the third time of asking.) How would you go about deciding to believe that I am a cabbage white butterfly? Seriously, what would you do in order to be able to pass the lie detector test while asserting that I'm a butterfly (Pieris brassicae to my friends)? For the moment, let's assume there is a lie detector that actually works. Are you unable to answer it? Is that because you were simply wrong when you said "deciding to believe in something one knows is not true" isn't a sign of mental illness. It is a sign of humanity. "? Are you going to admit that you were wrong or are you going to try to pretend that you never made the assertion (a bit like you said you hadn't strawmanned my argument when you plainly had)

Not to mention wars. On the other hand, our soft drinks industry might be helping in an unexpected way. http://en.wikipedia.org/wiki/Solar_water_disinfection

Without order sorting the bandwidth is limited to an octave at best. However the OP asked (albeit a long time ago) about "ID'ing organic compounds." and to do that you need a wider range- typically 400 to 4000 cm^-1 which is more than 3 octaves. Lisanke, I think you would benefit from looking at something like this http://en.wikipedia.org/wiki/Monochromator#Czerny-Turner_monochromator

Quartz is transparent to IR in the very real sense that you can use the IR absorption of quartz to measure it. http://www.hse.gov.uk/pubns/mdhs/pdfs/mdhs101.pdf Do you understand the relationship between the change in path length and the resolution of the spectrometer? You do need an order sorting filter. The diffraction angle will be the same for 2 µm as it is for the second order diffraction of 1µm and this sort of thing happens regardless of the grating spacing. A grating is much easier to make, but you do need order sorting filters, whether you like it or not. If I was using a lathe I'd cut a fine screw thread on a metal tube and then cut it along its length and open it out. However, actually,. I'd just buy a reflective grating on eBay. But the use of a zone plate made by turning a flat face on a lathe is interesting. You could also use an old LP record.

Because UV only works with clean water.

"Ok... I can only try to dissuade you from your belief that all church going folk are insane " strawman. I'm saying the people who believe in a God are delusional. Not all believers go to churches. Not all church goers are believers. However, given the name of the thread, only those people who believe in God are directly relevant to the discussion. You might have read what I said i.e. "Those who don't believe, but go to church anyway may well be sane." that's a very long way from all church goers are insane, it's an assertion that at least some are not. I would like to see how you come to the conclusion that all people in church know that the religion is nonsense. "The sane people who go to church on Sunday know very well that the crap preached to them isn't true," OK, that's the non believers suitably described as sane. But the thread isn't about non-believers. Iif there is one (or more) person in that church who is a believer in God then, they "don't know the delusion (the existence of God) isn't true. " because they believe that the delusion is true. And, by your assertion "Mentally ill people don't know the delusion isn't true. " So (The people in church who believe in God) don't know the delusion isn't true. and (tacitly, all, since you didn't clarify any subset) Mentally ill people don't know the delusion isn't true. so you can equate "Mentally ill people " with (The people in church who believe in God) . Re "Revisit my post to which you are responding. I said "If it is broken, then broken we are"." Speak for yourself. And, I see you still have yet to try to answer my question. How would you go about deciding to believe that I am a cabbage white butterfly? Seriously, what would you do in order to be able to pass the lie detector test while asserting that I'm a butterfly (Pieris brassicae to my friends)? For the moment, let's assume there is a lie detector that actually works.

At 47, I'm old enough to know that you should be able to cite a reason why you believe that "The sane people who go to church on Sunday know very well that the crap preached to them isn't true,". It also rather misses the point of the thread which says "People who believe in god are broken". Those who don't believe, but go to church anyway may well be sane. However those who do believe are, by your assertion, insane. In the meantime, how well are you getting on with explaining how you choose to believe that I'm a butterfly? Did you misunderstand that that was a question, or is there some other reason? Was the conclusion that you didn't need to answer it "a dishonest or mentally ill conclusion to make from what I said".