  Mini superspace cosmology treats the scale factor $a(t)$, the lapse function
$n(t)$, and an optional dilation field $\phi(t)$ as canonical variables. While
pre-fixing $n(t)$ means losing the Hamiltonian constraint, pre-fixing $a(t)$ is
serendipitously harmless at this level. This suggests an alternative to the
Hartle-Hawking approach, where the pre-fixed $a(t)$ and its derivatives are
treated as explicit functions of time, leaving $n(t)$ and a now mandatory
$\phi(t)$ to serve as canonical variables. The naive gauge pre-fix $a(t)=const$
is clearly forbidden, causing evolution to freeze altogether, so pre-fixing the
scale factor, say $a(t)=t$, necessarily introduces explicit time dependence
into the Lagrangian. Invoking Dirac's prescription for dealing with
constraints, we construct the corresponding mini superspace time dependent
total Hamiltonian, and calculate the Dirac brackets, characterized by
$\{n,\phi\}_D\neq 0$, which are promoted to commutation relations in the
quantum theory.
