Re: Binary stars

[Leigh Palmer <palmer@SFU.CA>]

> BTW Leigh, How do you distinguish with your terminology the difference
> between an infinite cylinder and a finite length cylinder?

One uses cylindrical symmetry for a finite cylinder only as
an approximation, i.e. for rho << distance from nearer end.

> I might add for folks' information; that one often sees the term "axial
> symmetry", which I believe to be the as the "azimuthal symmetry" to which
> Leigh refers.

I never remember what "axial symmetry" means. If it is
synonymous with azimuthal symmetry that's fine, but I always
have to ask. It sounds to me like it implies that z is the
ignorable coordinate. That's why I like the term "azimuthal
symmetry" (phi is ignorable). I think it is less ambiguous.

Leigh