Talk:Group velocity
Appearance
The group velocity of a wave is the velocity with which the overall shape of the wave's amplitude (known as the envelope of the wave) propagates through space.
I have NO idea what this means! "overall shape of ...amplitude" ? I thought amplitude was a number (scalar). Even if its a vector, tensor or other function, the claim (implicit) that it has a "shape" which propagates is unhelpful gobble-de-gook.
What about talking about wave composition? or "repeating units" (as in poly-"mers")