  Whether energy is conserved in a universe which keeps expanding is an
intriguing question. It is tempting to argue that the total energy within the
universe would have to increase as the universe expands. Upon more detailed
inspection the question is a lot harder to settle since defining what is meant
by energy or even what is meant by energy being conserved is a difficult
problem in general relativity. Using the definition of quasi-local energy
provided by Brown and York we try to answer the question in which sense the
total energy in an expanding (or collapsing) universe is conserved.
