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John Cuthber

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Everything posted by John Cuthber

  1. A lot of lawn weedkillers are based on hormones. I'm sure that some of them are on sale to the public here in the UK. They certainly used to be. I don't know about sales in the US or planaria. Search for products containing 2,4D
  2. Just a thought. If you are going to set yourselves up as the educated and informed voice of reason you might want to use capital letters.
  3. "and this relates to Nitrogen... How?" It doesn't; that was the point. The question is so absurdly vague it doesn't even ask about nitrogen.
  4. "Evidence-based government in the US We used to have it" When? I mean not just the US when did anyone have this? A major part of a government's job is economics and I think the evidence there is often poor. At best it's often a toss up between believing the left wing expert or the right wing expert.
  5. OK, so say I email in and claim to be a physics professor. How do you check my credentials? Actually I'm a professional chemist but I don't think my employer would be happy to be used as a reference for this sort of thing (which is essentially why I don't use my real name.)
  6. Imagine I got a hammer that weighed about as much as a person , say 140 pounds, and I lifted it 2 storeys up then dropped it on someone's head. It's not surprising the guy died. (and I'm not sure a cycle helmet would have saved him)
  7. This may help http://en.wikipedia.org/wiki/Henderson-Hasselbalch_equation So might the fact that one of the pKa s isn't important here.
  8. It's currently about 22 minutes past 7 in the evening as I write this. While that is a fact it's probably not one that you were looking for. Perhaps you could have been more specific.
  9. Probably any of them but you won't be able to get it back. Anyway, if you need to ask questions like that you probably shouldn't be using HF.
  10. I can't wait for someone to get this system up and running on a commercial basis. I will explain to my neighbour that it's a really great idea and that he really needs to get it installed. Then I will steal his electricity. Or, to put it another way, I forsee a problem with this technology. "Transistor radios were powered by RF exclusively (in the days before widespread distribution of batteries) and represented the first practical portable radios aimed at your average consumer, in the early 20th century" Sure about that?
  11. I can't help thinking that the real benefit will come once we get everyone else to sign up to some sort of ethical code. Why pick on scientists? As far as I know we are not particularly unethical to start with. A code of ethics for politicians would achieve far more.
  12. I do plenty of drinking but I don't drive so I'm unlikely to get busted the next day. I am also aware that (at least from my point of view) it doesn't take a very heavy drinking session to be still over the limit the next day. Pernod is noted for tasting of pernod the next day (etc). That's down to things like anisaldehyde rather than alcohol so it rather argues against alcohol being the sole factor. This assertion "the fact that CPL said he didn`t means nothing other than Not Enough," might be true but you cannot know because you don't know how much whiskey he drinks.
  13. "I`de like to see how Titration would work with the silver nitrate reaction!" Your wish is my comand. Personally I'd use fluorescein as an absorption indicator because it's pretty.
  14. Guess what, my dear parents were not generally watching when I was falling out of trees etc. Not because they didn't care but precisely because they did. Surely I'm not the only one who deliberately waited till there were no grown-ups about to tell me not to before doing something dumb. If CBS were being deliberately negligent of the duty of care they would be prosecuted (and possibly sued too) in spite of the "disclaimer". The disclaimer can only cover events that are not the result of CBS's actions. The kids may well hurt themselves. If that happens then a court will see if CBS were negligent. It may be that the court finds that the misfortune that befalls some child is an accident and that CBS are not criminally liable through negligence. The disclaimer will stop any civil claim at that point. I think that's all it can do. The problem isn't that CBS's lawyers insist on a disclaimer. The problem is that anyone thinks this is anything other than child abuse.
  15. If you are planning to weigh the AgCl then this is gravimetry*. If you are planning to use a solution of a known concentration and add exactly enough to ppt all the Cl then it's called titration. * Gravimetry is also the word for measuring the local strength of gravity.
  16. Presumably your talents and gifts don't include the use of capital letters, punctuation or how to use spoilers. Just out of idle curiosity, how likely was it that one of the teachers from your school would reply and what would you say to them here that you can't say in person at school?
  17. Water is miuch more viscous and doesn't have much oxygen in it so there's a lot of energy needed to pull enough water through the gills to get enough oxygen.
  18. I guess he's not fussed about whether you believe facts either. If it doesn't work with whiskey (and, unless you are calling him a liar, I think we can take that as a fact) then, since vodka and whiskey have similar alcohol contents it can't be due to alcohol. My personal guess is that it's at least partly due to acetaldehyde. but I still can't explain the difference between spirits.
  19. The blue/grey triangle shaded on the graph is the clue. The slope of that tangent is the change in y divided by the change in x. In this case its the change in concentration of butyl chloride divided by the time over which that change took place. The values can be found by reading off the axes. Look at the line drawn as a tangent to the graph. At 400 sec the concentration is 0.042M at 800 sec its 0.018M and so the difference is 0.024M. Divide that by the difference in time and you get the rate of change.
  20. http://www.britannica.com/eb/article-9020249/carbon-dioxide
  21. I got some from ebay but the easy way is to buy it from a chemical supplier. It's not a restricted product.
  22. Thanks for that reference. It seems I'm not the only one who thinks a thin layer of water won't help much "In 2002, Dr. Salmeron and colleagues performed an experiment. They dragged the tip of an atomic force microscope, resembling a tiny phonograph needle, across the surface of ice. "We found the friction of ice to be very high," Dr. Salmeron said. That is, ice is not really that slippery, after all. Dr. Salmeron said that this finding indicates that while the top layer of ice may be liquid, it is too thin to contribute much to slipperiness except near the melting temperature. In his view, friction is the primary reason ice is slippery. (The microscope tip was so small that its friction melted only a tiny bit of water, which immediately refroze and therefore did not provide the usual lubrication, he said.) Dr. Salmeron concedes, however, that he cannot definitively prove that his view is the correct one. "It's amazing," he said. "We're in 2006, and we're still talking about this thing." " Well, now it's 2007 and I don't see this as fully resolved yet.
  23. When I was a kid I used to climb trees, swim in the canal and ride a bike on main roads. Any of these could have led to my death (or to serious injury). Is CBS simply accepting that kids playing are sometimes exposed to danger and that they don't want to face an essentially unlimited lawsuit? Having said that, the whole idea seems wrong to me. It looks exploitative at best and I don't think children are born to be "used" in this sort of way. To me that seems to be a bigger problem than a contract that probably wouldn't be enforceable.
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