(Lansing State Journal, May 5, 1993)
Question submitted by Nicholas Troshak.
Magnetic fields are produced by moving charges. For example when electricity flows through a wire there are electrons, which have a negative charge, moving through the wire. This moving charge produces a magnetic field around the wire. You can demonstrate this principle by wrapping a long wire around a nail and connecting the ends of the wire to a battery. Each loop of wire around the nail produces a small magnetic field. The nail lines up and concentrates the fields created by the many loops and becomes magnetized.
The magnets that you have holding papers on to your refrigerator are permanent magnets. These magnets can be manufactured or can occur naturally. The reason some materials are naturally magnetic is due to their atomic structure. The way in which the electrons orbit the nuclei of these naturally occurring magnets resembles a wire loop. Each loop, or atom, produces a small magnetic field, and under the right conditions these fields work together, producing a strong magnet.
R. Lambert and Dr. P. Parker contributed to this article.