This is just a conceptual question that I've been personally wondering about. So light has a magnetic field wave perpendicular to an electric field wave. I don't quite understand the magnetic field wave though. I thought that magnetic fields were not supposed to have a beginning or end. They continuously travel in a loop from north pole to south pole. How then does light's magnetic fields work? Where are the north and south poles and where are the loops? How is it that the diagrams just depict linear magnetic field vectors? Diagram example: http://www.google.com/imgres?um=1&hl...,r:8,s:0,i:164 I have googled this to a great extent but have not been able to find an answer. Any help would be greatly appreciated. Thanks.