  Many advances in physics have in common that some idea which was previously
accepted as fundamental, general, and inescapable was subsequently seen to be
consequent, special, and dispensable. The idea was not truly a general feature
of the world, but only perceived to be general because of our special place in
the universe and the limited range of our experience. It was excess baggage
which had to be jettisoned to reach a more a more general perspective. This
article discusses excess baggage from the perspective of quantum cosmology
which aims at a theory of the universe's quantum initial state. We seek to
answer the question `Which features of our current theoretical framework are
fundamental and which reflect our special position in the universe or its
special initial condition?' Past instances of cosmological excess baggage are
reviewed such as the idea that the Earth was at the center of the universe or
that the second law of thermodynamics was fundamental. Examples of excess
baggage in our current understanding of quantum cosmology are the notion that
measurement is central to formulating quantum mechanics, a fundamental quantum
mechanical arrow of time, and the idea that a preferred time is needed to
formulate quantum theory. We speculate on candidates for future excess baggage.
(This article appeared in 1991 but is posted here for accessibility and
possible current interest.)
