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Suspending Magnets
Name: Paul
Status: student
Age: N/A
Location: N/A
Country: N/A
Date: N/A
Question:
What would happen if you took a basketball and lined the
inside with magnets, all positive facing in (towards the center of
the ball,) and then took a ping-pong ball and lined the outside with
magnets all positive facing out, and then dropped the ping-pong ball
into the center of the basketball-- would the force of repulsion be
greater than the force of gravity causing the ping-pong ball to
float in the middle of the basketball until it found a point of
stasis? I have tried to build a 'magnetball' myself but I was unable
to find magnets shaped in such a way that they would completely
cover the entire surface of both balls, as a result the spaces
between the magnets had the opposite polarity creating areas of
attraction.
Replies:
Paul,
It is not possible to make a CLOSED sphere with the outside being only
one pole. The magnetic fields from the inside surface would cancel the
field from the outside surface, even if you could get the magnets close
enough together. Unlike electric charge, magnets are not positive pole
at one end and negative pole at the other. Every molecule is a magnet.
Every zone of aligned molecules is a magnet. A day-to-day magnet is
actually many tiny magnets lined up with each other.
If you try to put strong magnets side by side, all pointing in the same
direction, they can join, but there must be a way for the magnetic field
to circle around from one pole to the other. If you somehow managed to
align all the molecules in a sphere, the magnetic fields from the inner
surface would still pass through the material to the outer surface, in
both directions. The material would behave like many very narrow
magnets with alternating alignments. It would work like half the
magnets were pointing inward and half were pointing outward, all
intermingled. There would not be a magnetic field within the ball.
If you did build this structure, with the zero field at the center, over
a short time the molecules would rotate within the magnetized material.
You would probably end up with one pole at one end and the other pole at
the other end, very much like the magnetic field pattern of the Earth.
Dr. Ken Mellendorf
Physics Instructor
Illinois Central College
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Update: June 2012
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