# What is the electric field part of an EM wave? Radiation field or the induction field?

Look at this image:

I wonder if the electric field is from the induction field from a vibrating electron or the radiation field? If it is from the radiation field, as I suppose, than can someone explain why they are perpendicular to me? As they have derived it from this link. It says that the magnetic field and the radiation field is in phase(in degrees! not in x-direction).

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Hi user7773, I think your question is already answered in physics.stackexchange.com/questions/20331/…. –  Alexander Feb 21 '12 at 17:06
Nja, not really. It just mention the electric field. Not how it is perpendicular. –  davinciho87 Feb 21 '12 at 17:36
This can be a simple plane electromagnetic wave in a vacuum, thus no electrons. There need not be a medium for these to exist. –  honeste_vivere Oct 3 '14 at 18:11