From: utzoo!decvax!duke!harpo!seismo!hao!hplabs!hplabsb!soreff
Newsgroups: net.physics
Title: Truly three dimensional instability
Article-I.D.: hplabsb.1268
Posted: Fri Jan  7 18:33:06 1983
Received: Sun Jan  9 01:53:59 1983

    Does anyone out there know of an example of a physical system with
an instability which truly requires a three dimensional representation
or description?  I don't mean a system where some vector quantities
need components in all three directions, but rather one where for each
direction, there is at least one physical function (temperature,
electrostatic potential, magnitude of magnetic field strength) which
varies along that direction in a way that is qualitatively important
to the instability.  Basically I am looking for systems which don't
have an analog in any system with full translational symmetry in any
direction, or with full rotational symmetry about any axis (which
would also allow a two dimensional representation).  A number of
instabilities (those associated with convection, for instance) can
produce three dimensional patterns (the hexagonal convection cells, in
this instance), but all the ones that I know of have two dimensional
analog, so the three-dimensionality of the system only affects the
size of critical onset parameters and the like, but not the
qualitative instability.  I'd like this to be a discussion question,
so please post answers to the net.	-Jeffrey Soreff
					(hplabsb!soreff)