Jump to content

John Cuthber

Resident Experts
  • Content Count

  • Joined

  • Last visited

  • Days Won


Everything posted by John Cuthber

  1. I thought that not drinking coffee made you a not mathematician.
  2. 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.
  3. Do you mean this? https://fr.wikipedia.org/wiki/Touline
  4. When the motor is running ,the rotor has a magnetic field, and it is moving post the coils of the stater. That moving field and coil of wire generates a voltage. It is traditionally called the "back EMF" The voltage opposes that from the mains supply. So, the current through the motor depends on the difference between the mains voltage and the back emf. If the motor is run at a low voltage it doesn't spin so fast and there is a smaller magnetic field produced by the rotor. So the back emf is lower. And so the difference between the mains and the back emf is higher and the motor draws more current.
  5. Well... yes, I think we can all agree to that (at least in general- there maybe short-term exceptions) And, while I realise it's not the right country, I hope you will forgive me for posting this link. I'm hoping that someone could do a similar analysis for Canada (and, even the US if they liked) https://www.taxresearch.org.uk/Blog/2017/11/27/the-tories-created-two-thirds-of-the-uks-national-debt/ Here in the UK (and, of course, it may be different elsewhere) the Right wing Conservative government have consistently borrowed more and paid back less. That seems to me to be running up "bad" debts.
  6. Just curious- it's not my field. I presume that much of the debt which that 8.2% of revenue is being paid on , is historical debt. Is it plausible that the money was borrowed in order to build and run hospitals, schools roads etc? If so, is it possible that the money saved/ earned by the state (depending how you look at it) by having a health better educated workforce with better infrastructure is more than 8.2% of revenue? If so, is it possible -even likely- that, had the previous governments borrowed more, and built, for example, better roads, they would now have more money today? That's kind of the point of most borrowing- you can invest it. Once you consider the notion of investment, it stops being simple addition and subtraction.
  7. Over here they managed that by the simple expedient of giving lots of money to rich people.
  8. It's fake. Probably (as Sensei says) a laser since that's probably the easiest and cheapest way to do it.. Any chemical which could light a match at a distance of a few inches would destroy the paper on contact.
  9. Then, whatever you do, don't elect a Conservative. They got elected here in the UK on a ticket of "Paying down the debt". Since then, they have borrowed more than all Labour governments put together and the national debt has doubled.
  10. That's OK, but don't let the internet find out.
  11. People tried. told them they were wrong. Then you told them that you were open minded. Great! Now looking forward to your evidence that we don't throw off practically all the pathogens we meet. Great! Still looking forward to your evidence that we don't throw off practically all the pathogens we meet. and so on.
  12. How will you know what is correct and what is incorrect? In general, we destroy them, rather than accumulating them. I do not still have all the colds or sore throats I ever caught. It's true that, for example, we never really get rid of some- like Measles- which is why it's very rare to get it twice. However, once we have fought them to a standstill, they are hardly pathogenic.
  13. Nice explanation of why the law includes the phrase "Beyond reasonable doubt".
  14. Strictly, that's also true of Rb- you just need to wait about 10^12 years for the unstable one to decay.
  15. SD cards, the cloud, or big hard drives.
  16. In principle, but you are likely to get fumes of SO2, so be careful.
  17. No. Even if gold was the same price as copper, it would still make sense to use copper for motor windings- because it is much less dense. (Copper is also a slightly better conductor.) As I said, part of the rarity of the use of the purple gold alloy is the cost. That's why I said So, once again, thanks for finding confirmation of my earlier post.
  18. No There is nothing which you can calculate from those data which has units of metres per metre.
  19. Thanks for finding a source which tallies with my view that nobody makes motor windings from gold, and that the current use of the purple Au/ Al alloy is rare.
  20. They often use aluminium because, while it isn't as good a conductor as copper or silver, it's a whole lot lighter. Gold would be a very poor choice for motors that change speed often. If gold suddenly became cheap, metallic purple jewelry would be more common. https://en.wikipedia.org/wiki/Colored_gold#Purple_gold However the energy cost in de-orbiting stuff is generally huge
  21. Thanks for the summary. It was a nice clear precis of the original work. It has saved many of us from the trouble (and, probably, discomfort) of reading the book. The book is utter tosh totally devoid of any basis in fact.
  22. It's also easy to refute most of the points raised. Many are just wrong, for example: Allergies are observed in most mammals. We are most likely to spot them among our pets https://www.msdvetmanual.com/dog-owners/skin-disorders-of-dogs/allergies-in-dogs https://thepigsite.com/disease-guide/sunburn-heat-stroke
  23. Reality doesn't agree with your idea of what is rational. And it isn't reality which has made a mistake.
  • 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.