... a spiral wave has a what???...A linear component!!! The stuff we're talking about, at a very basic level (i.e. BASELINE) is LINEAR... How do spirals and waves exist without a linear component????
Seems like we keep getting sucked into your rotational dynamics black hole... 665 posts later and we're still going in circles...
Is it linear? Fair enough -- Offer a dynamic model of waves and spirals that does not require consideration of angular momentum. I'll suggest one and offer my counterargument.
As a side point, gravity waves in a fluid such as water have no linear structural connections or actuations at all (and certainly none rigid). Yet the molecules of water circulating in the wave form obey the laws of angular momentum and conservation. They even concentrate angular velocity and kinetic energy by reduced radius of circulation. It is the conservation of that angular momentum that allows a body of water to lift, against gravity, from the surface of the surrounding fluid for a moment - without anything remotely like a structure, any linear push or pull, or any functional "springs." It is almost completely a momentum conservation process.
It is not a linear compression/decompression cycle like sound waves in air (which are mass-effect 'springs' of a sort), because water is incompressible. I suppose it boils down to whether you treat the body as a compressible or incompressible medium in the transmission of forces. Eighty year-old people don't compress so well (or at all, safely) so I know where I lay my money based on O Sensei's example.