A magnetic monopole is a (possibly hypothetical) elementary particle in the form of an isolated magnet with only one magnetic pole (a North pole without a South pole or vice versa). In other words, a particle with a 'magnetic charge' somewhat analagous to an electron with its 'electric charge'.
In 1931 Paul Dirac showed (in :Proc. Roy. Soc. A123, 60) that if even one single magnetic monopole existed in the universe (and the accepted form of Maxwell's equations is valid) then all electric charges (in the universe) would have to be quantized.
Note: We now know that all electric charges are quantised, but a magnetic monopole has never been observed in any experiment to date.
Ideas for new topics, and suggested additions / corrections for old ones, are always welcome.
If you have skills or interests in a particular field, and have suggestions for Wikenigma, get in touch !
Or, if you'd like to become a regular contributor . . . request a login password. Registered users can edit the entire content of the site, and also create new pages.
( The 'Notes for contributors' section in the main menu has further information and guidelines etc.)