[sdiy] MRI time dilation?

[KA4HJH]

>from what I remember messing with the stuff as a kid, no.. copper and
>aluminum just do not conduct magnetic flux very well. The windings
>themselves can be copper or aluminum, but the flux that is induced should
>have a xfer material be ferrous to get good flux xfer ratio. There is
>actually charts that show the flux acceptance/reluctance for various
>materials.

I don't know the physics behind this but I've seen the aluminum ring
demonstration a number of times. Put an aluminum ring on an electromagnet
connected to an AC supply. Switch it on. The ring goes flying off the core.
You shouldn't be standing in front of it when you switch it on.

As I recall their are non-ferrous metals in the rotor of a shaded-pole
motor, which works on a similar principle. All conductors interact with
magnetic fields, just not the same way. Most permanent magnets are actually
alloys of ferrous (iron, nickel, cobalt) and non-ferrous metals. I leave it
to our resident experts to explain why...


-- 
Terry Bowman, KA4HJH
"The Mac Doctor"