"Jonathan Silverlight" wrote
in message ...



In which case it seems to me that the interesting question is why some
objects are _not_ flat - the Oort Cloud (if it exists), globular
clusters, and elliptical galaxies, for instance.

Good point, I guess the interaction between Galaxies, black holes and
whatever else we have yet to discover may have big influences on how exactly
Galaxies end up the way they do.

Martin