This phenomena is strictly a mental schema, UNTIL an event contradicts THAT opinion.
I am befuddled. The other names of this concept are: parallel universes, alternative realities, and, as Enigcom says, dimensional presence.
David Bohm called such considerations, "the Theater of the Mind". He also proposed that our perceptions must be "Right". The only right perception is objectivity, because we are somewhat "pawns" in the theater of mental anomalies.
I cannot direct my mind to a conclusive fact due to my latest coincidence.
I am befuddled again.
The virtue of a highly evolved being embraces all people and things and dispels the darkness which isolates them.
Hua Hu Ching-primary lesson.