Gene, W4SZ wrote:
"Some people like to treat standing waves as poor distant cousins to
"real" waves, or perhaps as "only envelopes"."

Frederick J. Bueche & Eugene Hecht may have said it best in "Schaum`s
College Physics Outline": "Standing waves---These might better not be
called waves at all since they do not transport energy and momentum."

Best regards, Richard Harrison, KB5WZI