,
, and
form a
right-handed coordinate system.An electromagnetic wave can, for example, be generated by an
oscillating dipole. The waves will then spread out in time into all
directions. At all times and at all places, however, the E-field and
the B-field will be perpendicular to each other. The direction of
wave propagation is always such that the vectors ,
, and
form a
right-handed coordinate system.
In the video, one can see a particular electromagnetic wave
propagate in time. Shown are the E-field (red) and the B-field
(blue). A dipole undergoing simple harmonic motion is shown on the
left. The wave is moving along the x axis. The E-field is in the y
direction. The B-field is in the z direction. If one is sufficiently
far away from the wave source, the wave is approximately a plane wave
(=> All points in a plane perpendicular to
have the same E-field and B-field.
We have provided another, slightly different animation of the propagation of an electromagnetic wave which you can see by clicking below:
© MultiMedia Physics 2000