Could the Galactic disk heating be due to Globular Cluster impacts?
  So far, six mechanisms have been proposed to account for the Galactic disk
heating. Of these, the most important appear to be a combination of scattering
of stars by molecular clouds and by spiral arms. We study a further mechanism,
namely, the repeated disk impact of the original Galactic Globular Cluster
population up to the present. We find that Globular Clusters could have
contributed at most a small fraction of the current vertical energy of the
disk, as they could heat the whole disk to {$\sigma $}$_{z}$ = 5.5kms$^{{\rm -}
{\rm 1}}$ (c.f. the observed 18 and 39 kms$^{{\rm -} {\rm 1}}$ for the thick
and thin disks respectively). We find that the rate of rise of disk heat
($\alpha$=0.22 in \textit{$\sigma $}$_{z}$ $\sim t^{\alpha}$ with \textit t
being time), is close to that found for scattering by molecular clouds.
