Electromagnetic waves & influence

[Denton]

Why is it that electromagnetic waves, made up of constantly changing electric and magnetic fields are neither affected by electric or magnetic fields?...

 

[jtbell]

It's because Maxwell's equations are linear in the fields $\vec E$ and $\vec B$. They contain no terms involving products of the fields or their derivatives.

 

[astrokreng]

This is because electromagnetic waves are self-sustaining and do not require any external influence to propagate. The constantly changing electric and magnetic fields within the wave itself create a self-perpetuating cycle, allowing the wave to travel through space without being affected by any external electric or magnetic fields. This is known as the principle of superposition, where the fields of the electromagnetic wave combine and cancel out in a way that allows the wave to maintain its own energy and momentum. Additionally, electromagnetic waves do not have a charge, so they are not affected by electric fields in the same way that charged particles are. Similarly, they do not have a magnetic moment, so they are not affected by magnetic fields in the same way that magnetic materials are. This unique property of electromagnetic waves allows them to travel through a vacuum, as well as through different mediums, without being influenced by external electric or magnetic fields.