When we understand what to do with time in quantum gravity we'll have it done.
It can also be viewed as a different approach to the problem of quantum gravity.
This, however, is difficult to determine in the case of quantum gravity, for two reasons.
"Most of what we know about quantum gravity, for instance, we've learned in the last eight standard months."
This conclusion could change when quantum gravity is taken into account.
Nevertheless, the ground state energy has many implications, particularly in quantum gravity.
We do not yet know the exact form the correct theory of quantum gravity will take.
There ought to be a theory of quantum gravity - but nobody has been able to find one.
As a result, the effects of quantum gravity are extremely weak.
A theory of quantum gravity is needed in order to reconcile these differences.