**3.3. Conclusions on H_{0}**

To summarize, relative distance methods favor a value
*h*
0.6-0.7. Meanwhile the fundamental physics methods typically lead to
*h* 0.4-0.7. Among
fundamental physics approaches, there has
been important recent progress in measuring *h* via the
Sunyev-Zel'dovich effect and time delays between different images of
gravitationally lensed quasars, although the uncertainties remain
larger than via relative distance methods. For the rest of this
review, we will adopt a value of *h* = 0.65 ± 0.08. This
corresponds to
*t*_{0}= 6.52 *h*^{-1} Gyr = 10 ± 2 Gyr
for _{m} = 1 -
probably too low compared to the ages of the oldest globular clusters.
But for _{m} = 0.2 and
_{} = 0, or alternatively for
_{m} = 0.4 and
_{} = 0.6, *t*_{0}
= 13 ± 2 Gyr, in
agreement with the globular cluster estimate of *t*_{0}. This
is one of the several arguments for low
_{m}, a non-zero
cosmological constant, or both.