What is the extent of the electric field in electromagnetic waves?

AI Thread Summary
The discussion centers on the nature of electric fields in electromagnetic waves, specifically regarding the extent of the electric field generated by an electron. It clarifies that while photons can travel vast distances, the electric field does not extend infinitely; rather, it is confined to the wavefront that propagates outward over time. The relationship between electric and magnetic fields is emphasized, highlighting that they are interdependent and evolve along the time axis rather than merely in space. Ultimately, the electric field exists only within a certain distance from the source until the wavefront reaches that point. Understanding this temporal aspect is crucial for grasping the behavior of electromagnetic waves.
Savy
Hello.

Just a noob question about electromagnetic waves.
An electron "wiggles" and sends out a change in electric field, which creates a change in magnetic field, which creates a change in electric field etc etc.

My question is, because the photon travels to virtually infinite distances, does that mean the electric field of the electron is infinite? Or is it that the wavefront itself effectively extents the electric field indefinitely?

Sorry if this question doesn't seem clear, not very good at getting a point across via text!

Thanks in advance.
Savy
 
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I think I know what you are asking so I will try to answer.

Don't forget the time axis when talking about 'infinite'. Your electric and magnetic waves are plotted along the time axis, not a space one.

Alternatively the wave reaches a certain distance form the origin after a certain time. Before this time there is no wave beyond this distance. This of course refers to the wavefront.
 
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