Let's not forget about the habitable epoch of the early universe [1]. There's a good 7 million years near the beginning of the universe that in principle was inhabitable to Earth-like life. None can say if the physicists of that epoch (if there were any) had enough observational evidence to foresee their quickly approaching end.

[1] http://arxiv.org/abs/1312.0613

* do actually I believe there was early-epoch life sophisticated enough to think up physical theories? No, but what does that matter?