  The glass transition can simply be viewed as the point at which the viscosity
of a structurally disordered liquid reaches 10^{13} Poise [1]. This definition
is operational but it sidesteps fundamental controversies about the glass: Is
the transition a purely dynamical phenomenon [2]? This would mean that
ergodicity gets broken, but that thermodynamic properties of the liquid remain
unchanged across the transition if determined as thermodynamic equilibrium
averages over the whole phase space. The opposite view [3-6] claims that an
underlying thermodynamic phase transition is responsible for the dramatic
slowdown at the liquid-glass boundary. Such a phase transition (which shows up
in proper equilibrium phase space averages) would trigger the dynamic
standstill, and then get masked by it. A recent Monte Carlo algorithm [7]
introduces non-local moves for hard-core systems in a way which preserves
micro-reversibility. Here we use this method to equilibrate a two-dimensional
hard disc system far within its glassy phase. We show that indications of a
thermodynamic transition are lacking up to very high densities, and that the
glass is indistinguishable from the liquid on purely thermodynamic grounds.
