The key question here is time duration between reality and dreamworld....

Is it possible to mesure time inside a dream, using the time mesurement that we use in real life (hours and minutes)... and at the same time mesure the time outside the dreamworld? And compare durations? I think that would be really interesting.

Maybe we could start with hypnotic suggestion that woudl allow us to be conscient of the real time during a dream, or maybe we could go with calculations, starting by finding out when, during the rem cycle we started and stopped dreaming...

Just an idea.