XPost: sci.electronics.design   
   From: bill.sloman@ieee.org   
      
   On 19/02/2026 9:56 pm, J. J. Lodder wrote:   
   > Bill Sloman  wrote:   
   >   
   >> On 19/02/2026 7:49 am, Ross Finlayson wrote:   
   >>> On 02/18/2026 12:43 PM, Python wrote:   
   >>>> Le 18/02/2026 à 20:13, Ross Finlayson a écrit :   
   >>>> ..   
   >>>>> and, you know, magnetic monopoles, is widely employed   
   >>>>> in medical imaging and the like.   
   >>>>   
   >>>> No.   
   >>>   
   >>> Resonance imaging (NMR) is a thoroughly different mechanism   
   >>> than Roentgen rays.   
   >>   
   >> But as the name implies, it's nuclei of the atoms involved that exhibit   
   >> the resonance. It's a remarkably low energy effect, and you need   
   >> remarkably high magnetic fields to get it to give you a detectable signal.   
   >   
   > Nevertheless, it is easily demonstrated in the kitchen   
   > with some simple electronics.   
      
   Sort of.   
      
   https://en.wikipedia.org/wiki/Nuclear_magnetic_resonance   
      
   There are lots of different ways to exploit nuclear magnetic resonance.   
   The earth's magnetic field is high enough to let you devise experiments   
   that can demonstrate the effect on a kitchen table. Medical imaging   
   works a lot better with high fields. In 1979 I got to ask the EMI   
   Central Research NMR imaging development team why they weren't using   
   super-conducting magnets, and got told that you couldn't modulate the field.   
      
   The fact that you couldn't modulate the total number of flux lines   
   threading a super-conducting coil didn't mean what they thought it did   
   at that time.   
      
   --   
   Bill Sloman, Sydney   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)