  The ages of globular clusters inferred from observations depends sensitively
on assumptions like the initial helium abundance and the mass loss rate. A high
helium abundance (e.g., $Y\approx$0.28) or a mass loss rate of
$\sim$10$^{-11}M_\odot$ yr$^{-1}$ near the main sequence turn-off region lowers
the current age estimate from 14 Gyr to about 10--12 Gyr, significantly
relaxing the constraints on the Hubble constant, allowing values as high as
60km/sec/Mpc for a universe with the critical density and 90km/sec/Mpc for a
baryon-only universe. Possible mechanisms for the helium enhancement in
globular clusters are discussed, as are arguments for an instability strip
induced mass loss near the turn-off. Ages lower than 10 Gyr are not possible
even with the operation of both of these mechanisms unless the initial helium
abundance in globular clusters is $>0.30$, which would conflict with indirect
measurements of helium abundances in globular clusters.
