Speed of Electric Field: Is it the Speed of Light?

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The discussion centers on whether electric fields travel at the speed of light, c. It clarifies that while electromagnetic radiation travels at c in a vacuum, the propagation of changes in electric and magnetic fields also occurs at this speed. Participants note that fields themselves are not physical entities but rather represent influences that change over time. The concept of retarded times is mentioned, explaining that the observed influence of a moving charge is due to changes in the field propagating at c. Ultimately, the consensus is that while fields are not physical, their changes do propagate at the speed of light.
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"speed of field"?

Is it correct to say that a field (i.e. electric) travels at the speed of light?
We've been taught that only electromagnetic radiation in a vacuum travels so can we say that the effect of E travels at c also?
I always thought this to be the case but someone argued that fields are not physical and are 'just there'. Can anyone elaborate please?
 
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It is better to say that changes in a field propagate at some speed. For electric and magnetic fields in a vacuum, that speed is c.
 
ok that makes sense now.
I was a little confused because when using retarded times, it appears that the potential or field 'influences' at c but it's really because when using retarded times, a charge is moving and therefore the field is changing (and the change propagates at c).
thanks.
 

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