Dream world is not limited by the boundaries of physical space, nor by the constraints of physical time. In fact, as the Vedas and the Puranas describe and what modern physics is beginning to surmise, there are several worlds or lokas each with its own Time-Space continuum, substance-energy, forces and beings. It is for this reason that in thought we can travel through mind space and be almost instantly in contact with someone very far away. And if the person on whom you are thinking is also in the same mental corridor, he or she may receive what you thought. There are vital spaces, mental spaces, psychic spaces, spiritual spaces, each with its way of functioning and memory.
Affectionately,
Alok DA