Electricity and magnetism are fundamentally separate forces.

Electricity and magnetism entered early modern physics through visibly different phenomena. Static electricity could attract light objects or produce sparks; magnets acted persistently on iron and compass needles. There was no obvious reason to regard them as two manifestations of one interaction.

In 1820, Hans Christian Ørsted showed that an electric current deflected a nearby compass needle. André-Marie Ampère rapidly developed the connection between currents and magnetic effects. Michael Faraday then demonstrated electromagnetic induction: a changing magnetic environment could itself produce an electric current.

James Clerk Maxwell turned these experimental relationships into a unified field theory. His equations required changing electric and magnetic fields to sustain one another and predicted waves traveling at a speed matching the measured speed of light. Light therefore became part of the same theory as magnets, currents and electrical charge.

Modern electromagnetism does not say that electric and magnetic fields are literally identical in every circumstance. Their measured mixture depends partly on the observer’s motion. The deeper correction is that they are not independent fundamental forces; they are coupled aspects of a single electromagnetic interaction.