On Oct 18, 2011, at 9:55 PM, David Roberson wrote:
Hello Frank,
You have an impressive understanding of the flux pinning theory.
Can you give me an answer to my question? It appears that energy
can be put into the floating disk-magnet combination by pushing or
pulling against the disk. Where does the energy show up in the
system? Does the disk heat up a small amount as I push or pull on
the disk or does the magnet get the energy? This question may be
related to the amount of force required to displace the disk.
There may be important information revealed as a result of the
energy transfer. I eagerly await your answer.
Dave
Hi Dave,
Here is guess for you.
The magnetic pressure P = B^2/(2*mu0) is reduced in the volume
immediately below and above the puck, except in the thin volumes near
the puck of flux transiting the thin vortices in which lines of flux
are pinned. The magnetic pressure immediately adjacent to the sides
of the puck, and adjacent to the pinning locations is increased. Any
movement of the puck relative to a given magnet, provided the
movement does not involve a canceling symmetry, such as rotation
above a single magnet, or movement on a single magnet track, changes
the local B and/or volume in which the B resides, and thus magnetic
pressure, and thus energy of the system. Pushing the magnet into
place merely involves compressing the B into a higher average
pressure, and thus consumes energy. The energy in the B resides in
the polarized vacuum.
The pinned flux, the flux which travels through the SC, moves
relative to the fixing magnet if the SC orientation or position
changes. The movement of this close line flux superpositions with,
moves relative to, compresses and/or decompresses, the magnetic flux
which travels around the SC, resulting in energy changes in the B
field there, thus resisting motion.
Best regards,
Horace Heffner
http://www.mtaonline.net/~hheffner/
