Roy:

[snip]
Do the "vibrations" of electromagnetic waves you referred to in your
previous post have another name?

Roy Lewallen, W7EL
[snip]

Oscillations perhpaps?

I don't really understand your question... do you object to the term
"vibrations"? What would you prefer, oscillations, or...

It is well known by Physicists that lectromagnetic waves [at least in free
space and isotropic media] are generally consist of only transverse
vibrations,. this type of vibration is inherent in the formulation and
solutions to the Maxwell-Heaviside equations.

For examples of longitudinal or compressive vibratons for instance in a
taught wire like a guitar string, transverse vibrations or oscillations are
side to side, but longitudinal or compressional vibrations would be the very
tiny vibrations in the length of the guitar string. In systems where
longitudinal vibrations are supported, generally the velocity of propagation
of longitudinal vibrations will not be the same as that of transverse
vibrations.

For a detailed explantation of compressional-dilutive or longitudinal waves
in a variety of physical systems, cfr:

William C. Elmore, and Mark A. Heald, "Physics of Waves", McGraw-Hill, New
York, 1969.

--
Peter K1PO
Indialantic By-the-Sea, FL.