  We present a determination of the `Cosmic Optical Spectrum' of the Universe,
i.e. the ensemble emission from galaxies, as determined from the red-selected
Sloan Digital Sky Survey main galaxy sample and compare with previous results
of the blue-selected 2dF Galaxy Redshift Survey. Broadly we find good agreement
in both the spectrum and the derived star-formation histories. If we use a
power-law star-formation history model where star-formation rate $\propto
(1+z)^\beta$ out to z=1, then we find that $\beta$ of 2 to 3 is still the most
likely model and there is no evidence for current surveys missing large amounts
of star formation at high redshift. In particular `Fossil Cosmology' of the
local universe gives measures of star-formation history which are consistent
with direct observations at high redshift. Using the photometry of SDSS we are
able to derive the cosmic spectrum in absolute units (i.e.$ W \AA$^{-1}$
Mpc$^{-3}$) at 2--5\AA resolution and find good agreement with published
broad-band luminosity densities. For a Salpeter IMF the best fit stellar
mass/light ratio is 3.7--7.5 $\Msun/\Lsun$ in the r-band (corresponding to
$\omstars h = 0.0025$--0.0055) and from both the stellar emission history and
the H$\alpha$ luminosity density independently we find a cosmological
star-formation rate of 0.03--0.04 h $\Msun$ yr$^{-1}$ Mpc$^{-3}$ today.
