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John Cuthber

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Everything posted by John Cuthber

  1. Imagine that you had such a material, and you made a capacitor using it as the dielectric. The energy stored in a capacitor is proportional to the permittivity if the dielectric. Putting any voltage on a capacitor with an infinite permittivity would require an infinite amount of energy. Since that's not available either the permittivity must be finite or the "capacitor" has the strange property of never having a voltage across it. So I don't think an infinite permittivity is possible.
  2. A bullet that has just been shot into a block of wood will be warm. Work will have been done forcing the metal through the wood and some of that work will have been converted into heat. Since you do not (directly) know how much heat is produced you can not know how much energy is left as kinetic energy. However the momentum of the system remains constant and you can do a calculation with it that is similar to the equation you used for conservation of energy.
  3. John Cuthber

    The Wall

    About 2/3 of the Mexicans illegally present in the US got there by plane. Also, they are doing no harm, but contributing to the US economy. So the wall the the wrong answer to the wrong question. How come so many people swallowed the idea?
  4. I think I understood every word of that (except "o" which I think is a typo). However I didn't understand a single sentence. Is it just me?
  5. The mylar with a layer of Al is shiny. Catalysts aren't. That's because the very small particles of catalysts are too small to reflect light properly. If you make a nice shiny layer of, for example, Pt or Ni it will be a poor catalyst because it won't have much surface area compared to Pt black or Raney Ni.
  6. Dentine <> enamel. incidentally, since mice are rodents, and one of rodents' defining characteristics is that their teeth grow continuously the research is- shall we say- less useful than it might be.
  7. https://en.wikipedia.org/wiki/Cellular_respiration#Efficiency_of_ATP_production
  8. The enamel has no blood supply to provide nutrients- that seriously disrupts its chances of growing.
  9. Have you googled them? http://materials.springer.com/isp/crystallographic/docs/sd_1300485
  10. Quick, before you get banned, post the details of the next few national lottery winners- just the towns where they live will do. Then we will know you are not a sad deluded troll. Obviously, if you don't we can conclude that you really are a sad deluded troll.
  11. That's not a realistic goal. Water is fairly stable and doesn't dissociate. There are things (like sodium) that react with it. What are you trying to do?
  12. On a cold day dimethylsulphoxide and acetic acid are solids but if you add water they become liquids. Which material dissolved which? If you do this at -10 C it's pretty clear that the liquid alcohol acts as a solvent for the solid ice.
  13. Yes it does. It's just that you were hoping for a rational explanation.
  14. Yes, lots of things. The best known is probably alcohol, but also glycerine or sulphuric acid. Even things like gasoline will dissolve a little water.
  15. Can you find it on the wayback machine?
  16. Check with the local laws to see if you will need planning permission for the concrete block that you will need to mount it on.
  17. How do you plan to support/ move this quarter ton slab?
  18. Well, I could build a rotating kiln- but I can't help thinking that using a mould to get roughly the right shape would be easier. However, until the OP tells us what he's actually aiming for, there's not a lot of point speculating.
  19. No it won't. It will produce chloramines, but not Cl2 Perhaps you could expand on that. Ditto
  20. If the candle is in a box, make sure you have enough CO2 to fill the box.
  21. What accuracy do you need? If it's for a searchlight or a sun concentrator you can put up with much worse precision. If you tell us what you are trying to do we can probably help. Otherwise this might cost a lot more than it needs to.
  22. Unless you have a lot of spare money, you are not going to succeed.
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