You Cannot Split a Magnet Into Separate Monopoles

Most recent answer: 05/18/2008

Q:
Hi, Is it possible to "half", or split a bar magnet using an insulator or shield of some sort, effectively separating the poles, or isolating one of the poles? I envision something like a pencil inserted through a hole in a sheet of material with a rubber grommet as a seal. Would that split the poles, or would that in effect create 2 magnets? If it worked at all?
- john killin (age 37)
Cape Town, South Africa
A:

Nope.  If you cut one magnet into two pieces you get two similar magnets, each has a north pole and a south pole.   What you are trying to produce is called a magnetic monople.  They just don't exist.   The magnetic effects in ordinary magnetic materials is due to many tiny aligned current loops which produce what is called a dipole field. 
There is no fundamental reason why magnetic monopoles shouldn't exist and many experiments have been performed looking for them, even in rocks returned from the moon by astronauts. 
No luck.

LeeH

One possibility is that some magnetic monopoles were around in the very early universe, but became extraordinarily dilute as things expanded. At any rate, cutting a magnet won't make them.  Mike W.


(published on 05/18/2008)