Here's why:
* Magnetic monopoles don't exist: Unlike electric charges (which can be positive or negative), there are no isolated magnetic poles (north or south). Every magnet, no matter how small, has both a north and a south pole.
* Continuity is a consequence of Maxwell's equations: The fundamental laws of electromagnetism, known as Maxwell's equations, describe the behavior of electric and magnetic fields. One of these equations states that the divergence of the magnetic field is zero. This means that magnetic field lines always form closed loops, ensuring continuity.
Think of it like this:
* Imagine a bar magnet: The magnetic field lines emanate from the north pole, loop around, and return to the south pole. They then continue through the magnet itself, completing the closed loop.
* Even with complex arrangements of magnets: The lines of force still form continuous loops. They might twist and turn, but they will always connect back to their source, ensuring continuity.
This continuity principle is crucial for understanding many magnetic phenomena, from how motors work to how magnetic fields are used in medical imaging.
