Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Jumping rings eddy currents

  1. Apr 22, 2003 #1
    Guys & Gals

    Everyone has seen the jumping rings demonstration….

    Aluminium works fine, so does silver, iron and steel just stick to the coil

    Cut slots or drill holes in the disks and you get what you would expect


    Why doesn’t gold work?


  2. jcsd
  3. Apr 25, 2003 #2


    User Avatar

    Sorry, I have no clue what you are talking about but it sounds interesting so if you want to add some detail I will gladly learn more about it

  4. Apr 25, 2003 #3
  5. Apr 25, 2003 #4


    User Avatar

    Now I know what a jumping ring is but I am still clueless about what could make gold and silver behave differently in such an experiment. Is it a well known fact or something you have tried personally?
    Because the first thing I would think about is "was your gold real gold?"...

    ;) Dario
  6. Apr 26, 2003 #5
    18ct gold wedding ring, not quite pure but very close

  7. Apr 26, 2003 #6


    User Avatar
    Science Advisor
    Gold Member
    Dearly Missed

    have to say its curious gold wouldnt

    1. do you know the answer?
    2. did you actually try it?

    the way I interpret your post you actually did try it
    and are puzzled like us

    were the other rings you tried substantially bigger
    or smaller than the gold finger-ring?

    has the gold ring been cut and soldered closed?
    sometimes rings passed down in the family
    have had the size adjusted by removing a small

    dont see how either should make any difference but
    would like to know. sounds quite bizarre that gold would not jump
  8. Apr 26, 2003 #7


    User Avatar
    Science Advisor
    Gold Member
    Dearly Missed

    I wonder if the density matters.

    gold is heavier than aluminum
  9. Apr 26, 2003 #8
    Maybe it has something to do with gold's magnetic permeability or electric permetivity...
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook