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John Cuthber

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Everything posted by John Cuthber

  1. Yes it does. I have a dead soldering iron bit which says that it does... Also http://www.farnell.com/datasheets/315929.pdf Lithium / lead alloys (which have seriously different sized ions) are being considered for use in nuclear reactors. The only way to find out if lanthanides attack tungsten is to try it.
  2. It's an interesting idea. Even if you just split them into a few groups- high boilers, medium and low, you might make a second step so much easier as to be worthwhile. I'm pretty sure they will react with carbon. I suspect that you are near enough to the melting points of all but the most refractory metals that they wouldn't have the mechanical strength to build vacuum chambers from (unless you happened to be on the Moon).
  3. Stuff that's not digested by the intestines leaves by a different route. Calcium ions will form a solid precipitate with, for example, phosphate. Calcium phosphate can form kidney stones (and also bones). It is still calcium in the form of ions. Calcium metal reacts instantly with water.
  4. The problem is that you have not stirred the soup adequately. The requirement for a more or less fixed temperature while it melts is that the ice and water are in thermal equilibrium. That requirement is not met here.
  5. It's an interesting topic where stating something is on topic, but explaining that the statement is wrong is off topic.
  6. I never said it was. I said CaCO3 dissolves in the acid in the stomach- it does-and I said that the calcium is absorbed- it is. I never said where it was absorbed so...
  7. Religion(s) tried to pretend that we were the centre of the universe and that other religions were so wrong they were evil and should be killed for it.
  8. Calcium carbonate which enters the digestive system will usually react with the HCl in the stomach. It's famous for it. https://en.wikipedia.org/wiki/Antacid The resulting solution of calcium ions will be absorbed.
  9. It doesn't really matter but, how did anyone come to the conclusion that buttercream is different outside America?
  10. There are two major ways that food "goes off". Bacteria or other micro organisms grow on it or it is intrinsically unstable. You can kill the bugs by pasteurisation. However, something that has more sugar than anything else is probably not going to be attacked by microbes. (Jam is a way of preserving fruit by adding so much sugar that there is not enough water for the bacteria. On the other hand, mixtures of fat and water (like butter) are not stable. Even without bacterial help they go rancid. There's not much you can do about that except keep the product cold. What happens to the buttercream if you leave it (in a closed container ) for longer than the shelf life? That might help you work out how it is going off and that will help you work out how to prevent that change.
  11. If you do that the aluminium will short circuit the resistor and you won't get a reading. There are glues that will stand 210C without any trouble The biggest problem you face is that an object like that ring, in air, doesn't have " a temperature". Bit's of it will be warmer than others. It should be. It's not going to be the most accurate measurement in the world, but you probably don't need that. You can improve the accuracy significantly by putting some sort of insulation on the temperature probe so that the air doesn't cool it much. A scrap of glass wool is probably good enough
  12. The toxicologists take this into account. It is called "cooking".
  13. Pesticides are chosen to have low human toxicity. There's unlikely to be enough to be worth worrying about.
  14. On a lighter note... https://vectorbelly.com/electrical177.html
  15. At 100,000 K a transition needing 10.2 eV would be perfectly acceptable, but it still wouldn't be a rotation
  16. Swansont's actual day to day experience says it is. Which are you going to believe? Incidentally, if you want the "high school science" explanation, remember that lines of force repel one another. So they spread uniformly through the bore of the solenoid in order to keep as far from eachother as possible. Why would they not?
  17. You can get that transition, but the classical interpretation (i.e. the one involving an actual rotation) is that it is only the electron which spins, not the whole atom.
  18. Good point, I wonder what the OP thinks of them. https://en.wikipedia.org/wiki/Helmholtz_coil The important issue about them is that they work.
  19. We haven't finished with Science 1.0 yet
  20. I'm not sure if this has been raised. When this forum first opened were "rep points" a feature? If not a long term member might have a lower rep points per post ratio than a newbie, simply because their early posts couldn't attract "reputation "at the time.
  21. Get a hall effect probe. Measure the field. Come back to us if you discover anything "interesting".
  22. With an induction motor there is no electrical connection to the rotor. The only current in it is induced by the current in the stator. Studiot's diagram of them in series is misleading.
  23. I thought that not drinking coffee made you a not mathematician.
  24. I think the lower input voltage leads to a reduction in both speed and magnetisation. Both factors reduce the back emf. So it falls more than the mains voltage.
  25. Do you mean this? https://fr.wikipedia.org/wiki/Touline
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