We discuss the relationship between geometry, the renormalization group (RG)
and gravity. We begin by reviewing our recent work on crossover problems in
field theory. By crossover we mean the interpolation between different
representations of the conformal group by the action of relevant operators. At
the level of the RG this crossover is manifest in the flow between different
fixed points induced by these operators. The description of such flows requires
a RG which is capable of interpolating between qualitatively different degrees
of freedom. Using the conceptual notion of course graining we construct some
simple examples of such a group introducing the concept of a ``floating'' fixed
point around which one constructs a perturbation theory. Our consideration of
crossovers indicates that one should consider classes of field theories,
described by a set of parameters, rather than focus on a particular one. The
space of parameters has a natural metric structure. We examine the geometry of
this space in some simple models and draw some analogies between this space,
superspace and minisuperspace.Comment: 16 pages of LaTex, DIAS-STP-92-3
