Physics
is our friend.
We all know that a magnet -- whether a compass needle or the Earth -- has two poles. Cut a magnet in half (an experiment better performed with the compass needle ;-) ) and you end up with two magnets, each with its own north and south pole.
Electric charge (of course) doesn't work like that. We're accustomed to the notion of isolated positive and negative particles (e.g., electrons and protons).
That asymmetry between electricity and magnetism is puzzling, bec...
Published on August 20, 2013 08:00