Precisely! I was hinting at the fact your dream is factually demonstrating the awareness of co-existing environments as experienced by the same individual.

The physics proposition hits at the possibility for their future discoveries, eventually only. They are not there yet in their experiments. That said they aren't done trying in the least.If scientists and spiritualits would coordinate more, science would have more targeted and relevant proposal for study.

And, to the point of the quantum physists, ordinarily, known living entities are normally unaware of these co-concurrent realities, that is what was depicted in physics in the "double-slit experiment"... But you were! And that is extraordinary! Yet it is ordinary for you, since you maintain the ability on a routine basis. 

What is even more fantastic is the awareness of existing in concurrent dimensions, but also additionally, tuning into another reality telepathically or as in a day-dream. That requires the psychic ability to totally transfer reliance of and on this so perceived concrete realm we all live in into other realities.

Quatum physics would only eventually stumble on such phenomena, or access it by sheer speculation. Otherwise, positing the right formula wouldn't happen, since observation alone (without the contribution of spiritualists) may not never happen.

So there is creciendo levels of complexities:

1. The slit-experiment, of understanding that there (can) exist two con-current realities. And according to science or the book of Yoga Vashishtha by yogi Valmiki, such realities are only existing upon observation.
2. Being simultaneously aware of con-current realities, contradicting point-1.
3. Being in point-2 and also relating to a third reality!

This demonstrably says that point-1, as stipulated above is insufficient and very limited in its purview of the possibilities of human capabilities and (spiritual) evolution.

Just because a limited entity is incapable of being aware of anything happing that is not under its nose should not be a basis for denying that possibility existing otherwise.

Perhaps one way could be pay attention to the moment before lapsing into sleep or right before waking from it. At those moments these realities intersect and constitue a cross over split moment which can validate the awareness into con-current realities. Of course this concept also comes with the acceptance of dreams a belonging to genuinely existing realities, along with the faculty of keen psychic observation.