What you describe is only a near field effect, so it isn't properly an EM wave at all.k9b4 said:If i have a charge in a vacuum, and I oscillate it at some frequency in x direction, other charges along the x direction will be caused to oscillate in the x direction.
So why was I always taught that the direction of oscillation is always perpendicular to the direction of travel for EM waves?
Yes, light can travel as a longitudinal wave under certain conditions. In a vacuum, light behaves as a transverse electromagnetic wave. However, when passing through a medium such as a gas or liquid, light can exhibit properties of both longitudinal and transverse waves.
A longitudinal wave is a type of wave where the particles of the medium vibrate parallel to the direction of wave propagation. This is different from a transverse wave, where the particles vibrate perpendicular to the direction of wave propagation.
Sound waves, seismic waves, and pressure waves are all examples of longitudinal waves. In some cases, light can also behave as a longitudinal wave, such as in certain types of spectroscopy or in the near-field region of an antenna.
Yes, light can only travel as a longitudinal wave in certain mediums. In a vacuum, light behaves as an electromagnetic wave, which is transverse. However, when passing through a medium with a high refractive index, such as a solid, light can exhibit properties of longitudinal waves.
The wavelength of a longitudinal wave is typically longer than the wavelength of a transverse wave. This is because the particles in a longitudinal wave are oscillating parallel to the direction of wave propagation, while the particles in a transverse wave are oscillating perpendicular to the direction of wave propagation.