Jump to content

John Cuthber

Resident Experts
  • Content Count

  • Joined

  • Last visited

  • Days Won


Everything posted by John Cuthber

  1. If you start with a molecule or atom in an excited state then you can ionise it using relatively low energy photons. There is no theoretical lower limit to this so even radio frequencies could ionise something that was already sufficiently nearly ionised.
  2. What are you doing that needs that dry an atmosphere? Anyway, the water permeation through the gloves will make more difference than the drying agent you chose.
  3. The point is that yes a magnet can push metal, but only if it's the right metal. As a matter of fact, magnets push water but not very hard.
  4. How will we know when we have won ie what will be the state afterwards? Are we getting measurably closer to that state? If we are not doing so then are we at a stalemate? Does a stalemate that keeps killing our troops count as anything other than losing slowly?
  5. If you assume that the aquarium pipe is pretty soft then the end plugs won't move in or out. The water pressure will squash the pipe until the pressure in it is 3 bar. There will then be the same pressure inside the pipe as outside it so there's no net force on the plugs. If you used a stiff metal pipe or very flexible plugs then the plugs would move in. If you used stiff plugs then the pipe would deform and they would stay put.
  6. "I believe part of bascule's point was that the polonium is "glued" to your lungs by tar, whereas the potassium in your food just passes through." It's true that the K passes through, but since I keep replacing it by eating this doesn't matter much. I'm still roughly 8000 times more radioactive than the Po in a cigarette. There's Po in food too; less than in cigarettes but most people eat more food than they consume tobacco. http://www.ncbi.nlm.nih.gov/sites/entrez?cmd=Retrieve&db=PubMed&list_uids=11225703&dopt=Abstract I have a good reason for ignoring the assertion that Po in smoke is responsible for the lung cancers in smokers. Typical indoor air has levels of radon about 50Bq per cubic metre. (the action limit is about 3 times higher) I breathe about 20 L/min so I get through a cubic metre in about 50 min. That's roughly 1 Bq per minute of radon that I breathe. The Rn is, of course, accompanied by the decay products which are typically stuck to dust particles. A lot of this is cleared out by the various mechanisms but since I keep renewing it that's not as much help as it looks. So I get exposed to the effects of roughly 1 Bq of each of the 2 isotopes of Po in the decay chain as well as the other things (2 Bi and 2Pb isotopres). In order to double my inhaled ,Po- derived, radiation exposure I would need to smoke a cigarette or 2 every minute (assuming all the Po in the cigarette ends up in my lungs which is questionable). Nobody smokes that much, yet smokers have incidences of cancer far more than twice the incidence of cancer found in non smokers. The issue here is not "we ignore it because they are smokers who should know better"; it's "we ignore it because it's not significant compared to background exposure". Smoking certainly adds to your Po intake, but not much. A 20 a day smoker takes in an additional 20Bq of Po A non smoker takes in about 1500Bq by breathing. The difference between 1520 and 1500 is not a plausible cause of the raised cancer rates in smokers. The tobacco industry is guilty of some pretty poor behaviour but this isn't a big deal. BTW, here's the bit from that paper that you seem to be ignoring "The Martelll "Hot Particle Theory" has been addressed in the past and has apparently lost popularity in the scientific community ".
  7. "So your argument is why not leave a radioactive compound in cigarettes because cigarettes contain other carcinogens?" No My argument is that the tiny ammount of Po in tobacco is unimportant compared to other toxins there. Removing it would be like trying to remove the lead- sure, you could do it, but it would make a lot more sennse to spend the money on anti smoking campaigns. "That would be a strawman which confuses a fatal dose with a carcinogenic dose." No it's an illustration of how small the quantity is. Comparing one carcinogen (Po) with 2 others (Cd and As) doesn't look unreasonable to me. There's another really important distinction between food and tobacco. Nobody really needs tobacco; if it all disapeared tomorrow it wouldn't kill anyone. Surely it makes more sense to worry about other things first. Natural K gives about 30 Bq/Kg. How much more radiation am I exposed to from the K in my food than from the Po in cigarettes? Well, I'd need to smoke a lot if the figure given here is right. http://www.npp.hu/mukodes/aktivitas-e.htm Am I worried about this? No, not even taking the effectiveness of alphas or the cumulative effect from the Po into account.
  8. "Perfect example of repititious propaganda regurgitation. Just say it over and over enough... Still waiting for your facts and evidence to support your claims...any of them. " It must be true, it's on CBS. http://www.cbsnews.com/blogs/2007/07/09/couricandco/entry3033134.shtml
  9. "Send a letter to the Department of Energy suggesting they regulate nuclear materials in tobacco the same way they regulate other nuclear materials. " I understand the guy you want to is called NORM. Probably the main reason this is being ignored by the authorities is that it's not very important. If they took all the Po out of tobacco there would still be plenty of other carcinogens left so what's the point? The quantity of Po in cigarettes is estimated as about 10 Bq each. So Mr Litvinyenco (sp?) could have got his fatal dose by smoking about a billion cigarettes. I think the ounce and a half of lead he would have picked up might have got him first. Failing that the couple of ounces of cadmium or the quarter ounce of arsenic might have taken him out. http://www.ncbi.nlm.nih.gov/sites/entrez?db=pubmed&list_uids=11941445&cmd=Retrieve&indexed=google It's not as if the same fertilisers are not used for other things. Brazil nuts often have raised radium levels but that's not going to stop me eating them
  10. Galton, the father of eugenics, made the same point (about the higher fertility of "the lower classes") in 1883 IIRC. Since then the standards of living and of education have increased more or less continuously.
  11. "In a similar way to how you see in IR" I don't see in the IR; that's pretty much the definition of IR. There is a difference between saying these things look the same (ie have the same visible reflectance) but don't have the same IR reflectance (which is common enough) and "these things look different in the IR" which only makes sense if you can look in the IR which you can't. I know things can reflect IR or UV differently, even if they look the same. In fact, everything does. If you look at a large enough range of the spectrum then no 2 things will reflect identically unless they are the same material. That's why I sugested using, for example, sand to look like sand. I'm still trying to work out what the OP's question meant.
  12. I think YT2095 is most of the way to the right answer. Almost all "polycarbonate" is bisphenol A polycarbonate. Comparison of the IR against a known sample is easy and (with the right kit) non destructive. You can hydrolyse the stuff and get the monomer (well, I'm not sure about getting the CO2 part of it) but as YT2095 says it's slow. While this reaction is slow, it's quite fast enough to damage polycarbonate objects, in particular alkalies reduces the strength and, since polycarbonate is usually used where its strength is important, that's bad news. Pyrolysis would probably give fairly recognisable debris if you GCMS it. What sort of kit do you have access to?
  13. "Yes, you can make things that look different in IR or UV than they do in the visible." I know how things look in visible light; how do things look in UV and how, unless your eyes are UV sensitive, do you know? Seriously, what does that sentence mean?
  14. "My point, was on this issue, was that IMO smoking is a *something to do* habit, opposed to some compulsion to feed a chemical into the brain." I know a number of ex smokers who don't share your opinion. The medical establishment tends to agree with them. The success of nicotine patches also indicates that this is a real chemical addiction. "The smoke related cannot be determined IMO." Statisticians and epedemiologists do not share your opinion on this.
  15. What do you mean by " way of making an entire material "? All that article says is that, in the same way that things are camouflaged by making them roughly the same colour as the background, they can be camouflaged from the point of view of an IR camera by making sure they have the same IR reflectance spectrum as the background. A fairly obvious wayto do this it to cover them with the same material as the background. For example, if you want to hide your tank in the desert, make sure it's covered with sand. If you want to hide it in the forrest, cover it with leaves. None of this will help if the enemy has thermal imaging gear.
  16. Intrerestingly, we now have proof that man can create life but no such proof for God. Does this mean that if God is subsequently found to be able to create life He is playing man?
  17. Lucaspa, The images raise awareness of both greenpeace and the whaling. I wonder how you expect greenpeace to do anything without raising money to cover the costs of doing it.
  18. "Then lets move to Asbestos, which claimed was the cause for ALL respiratory problems for years" Who made any such claim?
  19. Well, OK I agree that if your father died in a crash but it's listed as smoking related then the stats are skewed. I'm pretty sure that the statistical link between smoking and, for example, lung cancer is so well researched it's practically certain. I work measuring things- generally concentrations of pollutants in air. I know that some time ago when I was involved in measuring exposure to a chemical that people were working with and some other people were asking the same workforce to fill in a questionnaire about health, lifestyle etc. we got a rather disappointing result. The measurements of chemical exposure we took were very badly correlated with the health issues that the people had. The only statistically significant observation was that respiratory ill health correlated with smoking. That wasn't what we set out to find- it's just such a big effect it tends to swamp other things. If you look at demographics you find a whole lot of interrelated effects. If you look at incidence of lung cancer in a particular group like 70 year old men, then the stats are pretty clear. You find the highest incidence among heavy smokers, next highest among those who worked or lived with smokers or who smoked a bit and very low incidence among those who were not exposed. Prior to WWI lung cancer was a rare disease- even among the elderly. Nobody smoked. Now it's relatively common and a lot of people smoke. There was a ban on smoking in public places in Scotland quite recently- allready the statistics are showing the benfit of the reduction in smoking that resulted from this. Another point is that, like all drugs, nicotine has side effects and these are not generally benficial. The other trash in smoke doesn't help, but don't forget that nicotine is about as toxic as cyanide.
  20. I'd not bother with magnetometry. I'd dissolve the tablets in dilute acid, oxidise with H2O2 to get it all into Fe(III) then measure it colourimetrically. If I wanted to be classical about it I'd not oxidise the extract, I'd send it through a Jones reductor and then titrate the eluant with KMnO4 I have a feeling that you would need to do some sort of purification of the coffee extract before you could do a UV determination on the caffeine. I'd bet on chromatography. Not sure about the sunscreen- some sort of absorbtivity measurement.
  21. Don't forget that all the concentrations there have to be expressed as normality ie gram equivalents per litre (which is that same as molarity for nitric acid, but not for sulphuric). Only bother to read the next bit if you would otherwise point out the error. Strictly the units only need to be g eqiv / volume- it would still work in cubic feet but that's just complicating things.
  22. I think insane alien is mistaken. It would work. The alphas would plough into the other plate and charge it + while the electrons left behind would charge the alpha emmiting plate -. The same goes for the betas (the other way round). In fact, you only need one source.
  23. Also, while it's hot make sure it doesn't oxidise in air and give zinc ozide and SO2. If you are trying to get something to glow in the dark then I think the big problem is that the real stuff is made in a rather complicated way to get the best performance.
  24. Interesting chain of logic. I asked precisely one question; it was this "Still, what other product can you think of which, when used in accordance with the manufacturers instructions, has a 50:50 chance of killing you?" It seems the answer is "There is a 100% chance that eating carrots will kill you. A survey made in 1900, showed that every one surveyed had at some time eaten a carrot or carrots. Almost all are now DEAD, and the couple still around really look bad, expected to die soon." BTW, are you sure about what you said. I'm quite happy to believe that they record incidence of tobacco use on death certificates. Are you sure that's the only way they decide that tobacco is the cause of death. I know the medical and legal professions can be idiots at times but that one seems to be a step too far. If it is then, since they don't do that in the rest of the world, the aparent risk from cigarettes in the USA would be practically 100% whereas it's different elsewhere. Surely that would becom a ludicrous anomaly. Practically everyone has tried smoking once. Does this mean that 100% of deaths in the USA are recorded as smoking related?
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.