Brian Gaff wrote:
Hmm, a bit of a cop out really.

That's my thought about dark matter and dark energy. They feel like the
new epicycles, a cop-out until something better can come along.

For example, some are trying to explain observations without dark
matter:
http://www.iop.org/EJ/abstract/1475-7516/2005/05/003

Right or wrong, it shows you don't always have to use dark matter to
explain mysterious observations.

Mike Miller