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John Cuthber

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Everything posted by John Cuthber

  1. Except that it means something different. Specifically, it's an insult to the Hawaiian language to say that it's phonemes are "least", rather than that they don't use many.
  2. None of that box will reflect UV well. Did you understand this bit of what I said?
  3. Given the yellowish colour of that card, I would say it will absorb UV . If it was white card (or maybe blue) I'd expect it to reflect it. The problem is that you can't see UV so it's hard to tell
  4. Does this help? https://www.sigmaaldrich.com/catalog/product/aldrich/r350893?lang=en&region=GB Why do you want an IUPAC name for it?
  5. It's a radioactive atom. It will decay; once. There will be a brief flash of light. But there won't be any indication of the path the molecule was following when that flash happened.
  6. Fewest. (Well, it's a discussion about words..)
  7. If you just want to count words should you bother with all the variations? If I know the verb "walk", I can deduce some of the variations "walks" "walked" "walker" etc I'd need to learn the use of "walk" as a noun, separately. But from that, I can deduce a plural- "walks" If I was counting the words in a language with a view to choosing one to learn, I might not need to count the words like "wugs" which I'll never need to remember because I can "create" them when needed. But do I count walk(v) separately from walk(n)? Perhaps I should. To the extent that there's a rule in English for making verbs into nouns, I should go to a walking, in the same way that I go to a meeting. It looks very much like the answer to the question "Which language has most words" is "it depends" BTW, since the title of the thread lacks a question mark, it is a statement. So what's "which language"?
  8. Yep. Just make sure it's a randomly chosen spectroscopist.
  9. Mainly wrong. For a start https://en.wikipedia.org/wiki/Infrared_spectroscopy#Liquid_samples Also, re" We are only interested in motion that can lead to translation (ie evaporation) and that is the first one on my list." No If you look at a simple molecule like water you can calculate (quite easily) the number of possible vibrational modes it has. Each atom can move in any of 3 directions, (x,y and z). There are 3 atoms in a water molecule. So there are 3X3= 9 possible ways in which the atoms can move. But three of those correspond to rotations while (and here's the important bit) three of them correspond to translations. So there can be no more than 3 vibrational modes for water- it absorbs (fundamentally) at just 3 wavelengths. https://en.wikipedia.org/wiki/Infrared_spectroscopy#Number_of_vibrational_modes So the movements that you are interested in- the translations- are definitely not vibrations. (Just in case you are wondering, for linear molecules where rotating about the axis of the molecule isn't defined, there is one less rotational motion and thus 3n-5 possible vibrations.) Actually, what you want is a variable restoring force- if it varies linearly with distance you get a sinusoidal vibration. Molecules have bonds. Those bonds behave (classically) as if they're springs.
  10. "Do molecules below the surface of the liquid evaporate?|" Usually, but... https://en.wikipedia.org/wiki/Cavitation
  11. Vole = rearranged love letters. Yes and no...
  12. All of them; but by proxy.
  13. I'm not actually sure about that. Would it need to be stronger than a stone arch? If it is x times thicker it weighs x times more, but there's x times more stuff to hold it up.
  14. Is now. DD reactors exist. I'm thinking of making myself one as a toy. https://en.wikipedia.org/wiki/Fusor
  15. To be fair, while "zero" is the right answer, it's not obvious. So, here's the proof. https://en.wikipedia.org/wiki/Shell_theorem#Inside_a_shell And now that the only scientific question posed has been answered, I don't see any reason for this thread to remain open.
  16. The OP starts with "ok i think i may have phrased it wrong " and that's a good honest statement to make. But it does make discussions about exactly what he meant, a bit tricky. It's true that he didn't say anything about explosives. But If I ask "what's the heaviest mammal?" I'm going to get answers that relate to whales. There's some clever stuff with diamond anvil presses that get to about 10 million bar. But that's not really chemical. I think explosions get to nearly a tenth of that . There are some chemical reactions that take place in the range between those two. Metallic oxygen forms at about a megabar. So the decomposition of metallic oxygen would generate about a megabar. Does that count?
  17. Do you mean a rugby ball? It depends on the azide some aren't explosive, others are. ANd sometimes people accidentally convert the first group into the second. Nitrogen is good, mainly because the NN bond in N2 is strong. Making nitrogen gas generally releases a lot of energy and a gas. Those are both good for high pressure generation.
  18. This may be of interest. https://en.wikipedia.org/wiki/Trauzl_lead_block_test
  19. "Can something non directly exposed to fire start burning?" Yes. It is referred to as "non piloted ignition" https://www.govinfo.gov/content/pkg/GOVPUB-C13-2aca434d0a907ff2aff50e4308d18e98/pdf/GOVPUB-C13-2aca434d0a907ff2aff50e4308d18e98.pdf Make sure the house is surrounded by a wide lawn.
  20. Strong solutions of urea, glycerine, and/ or propylene glycol might be better solvents than water. It's possible that the caffeine is in suspension rather than solution. Why would you bother?
  21. Are you volunteering to go up against the guns first? If not, you understand why we are still talking about money. It's quite close to being the same thing.
  22. I don't think it will be the end of the NRA, but maybe it will be the beginning of the end. It's not my field; are there any "competitor" organisation? If there was an organisation that could say "We are a bit like the NRA, but less corrupt", they might do well enough to take over.
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