  The motion of a test Dq-brane in a Dp-brane background is studied. The
induced metric on the test brane is then interpreted as the cosmology of the
test brane universe. One is then able to resolve the resulting cosmological
singularities. In particular, for a D3-brane in a D5-brane background, one
finds a 3+1 dimensional FRW universe with equation of state $p = \ed$. It has
been argued that this may have been the dominant form of matter at very early
times.
