  Fourteen classical double radio galaxies with redshifts between zero and two
were used to determine the cosmological parameters $\Omega_m$,
$\Omega_{\Lambda}$, and $\Omega_k$, where these are the normalized values of
the mean mass density, cosmological constant, and space curvature at the
present epoch. A low value of $\Omega_m$ is obtained, and $\Omega_m = 1$ is
ruled out with 97.5% confidence. The low value of $\Omega_m$ determined using
the radio source method described here is also indicated by several independent
tests. Thus, it appears that either a cosmological constant, or space
curvature, is significant at the present epoch. This means that the universe is
undergoing, or has recently undergone, a transition away from a state of matter
domination and into a state where either a cosmological constant or space
curvature is determining the expansion rate of the universe. The low value of
$\Omega_m$ presented here and by Guerra & Daly (1998) means that we can state
with 97.5 % confidence that the universe will continue to expand forever.
